Faculty of Computers and Information

Minia University

Academic Year: 2025 / 2026

DuoCodo

Gamified, Arabic-Centered Programming Learning Platform and Application

Project Team Members

#	Name	Dept	Email
1	Mohamed Mostafa Amer Abdelkader	CS	muhammed.mustafa.work@gmail.com
2	Mohamed Ragab Abdelhafez Mehran	CS	ragab.168926@gmail.com
3	Alaa Mohamed Abdelhakeem Ahmed	CS	alaahakeem58@gmail.com
4	Ammar Emad Ahmed Azmy Zewain	IS	za0663008@gmail.com
5	Yassin Khaled Khalaf	IS	yassenkhaled927@gmail.com
6	Marwa Farid Mohamed	IS	marwafarid366@gmail.com

Under Supervision of

Supervisor

Dr. Rehab Emad El-Dein

CS Department

engrehab992@gmail.com

Teaching Assistant

T.A. Mohammed Shaaban

CS Department

mohamed.shaaban@gmail.com

List of Figures

Figure 3.1: Development Team Roles
Figure 3.2: Net Profit per Year
Figure 3.3: Cumulative Revenue vs Cumulative Cost
Figure 4.1: Decomposition Diagram Part 1
Figure 4.2: Decomposition Diagram Part 2
Figure 5.1: Use Cases Diagram
Figure 5.2: Manage User Accounts
Figure 5.3: Assign User Role
Figure 5.4: Monitor Platform Analytics
Figure 5.5: Review And Filter System Logs
Figure 5.6: Remove Inappropriate Content
Figure 5.7: Issue User Warning
Figure 5.8: Design Learning Path
Figure 5.9: Register Account
Figure 5.10: Login to System
Figure 5.11: Create Course
Figure 5.12: Create Lesson
Figure 5.13: Add Multimedia Content
Figure 5.14: Localize Content
Figure 5.15: Categorize Exercise Difficulty
Figure 5.16: Udate Course Materials
Figure 5.17: Review Student Submissions
Figure 5.18: Manage Course Structure
Figure 5.19: Create Coding Exercise
Figure 5.20: Validate Exercise before Publishing
Figure 5.21: Contribute to Learning Path
Figure 5.22: Register Account
Figure 5.23: Login to System
Figure 5.24: Recover password
Figure 5.25: Choose Learning Path
Figure 5.26: View Lesson Content
Figure 5.27: Complete Exercise
Figure 5.28: Track Progress
Figure 5.29: Learn XP and Level Up
Figure 5.30: Set Language Preferences
Figure 5.31: Bookmark Lesson
Figure 5.32: Share Solution
Figure 5.33: Enable Two-factor Authontecation
Figure 5.34: Practice Coding
Figure 5.35: Practice Coding with Blockly Editor
Figure 5.36: Receive AI-Powered Hints
Figure 5.37: Complete Certification Track
Figure 5.38: Class Diagram - Core User and Authentication System
Figure 5.39: Class Diagram - Learning Content Management
Figure 5.40: Class Diagram - Submissions and Code Execution
Figure 5.41: Class Diagram - Exercises, Attempts and Code Analysis
Figure 5.42: Class Diagram - Certification and Gamification
Figure 5.43: Class Diagram - Administration and Platform Management
Figure 6.1: Entity Relationship Diagram - User Management and Authentication
Figure 6.2: Entity Relationship Diagram - Learning Content and Course Structure
Figure 6.3: Entity Relationship Diagram - Submissions and Code Execution
Figure 6.4: Entity Relationship Diagram - Exercises, Attempts and Code Analysis
Figure 6.5: Entity Relationship Diagram - Certification and Gamification
Figure 6.6: Entity Relationship Diagram - Administration and System Management
Figure 6.7: Database Schema - User Management and Authentication
Figure 6.8: Database Schema - Learning Content and Course Structure
Figure 6.9: Database Schema - Submissions and COde Execution
Figure 6.10: Database Schema - Exercises, Attempts and Code Analysis
Figure 6.11: Database Schema - Certification and Gamification
Figure 6.12: Database Schema - Administration and System Management
Figure 7.1: Login Screen
Figure 7.2: Registration Screen
Figure 7.3: OTP Verification Screen
Figure 7.4: Password Entry Screen
Figure 7.5: New Password Creation Screen
Figure 7.6: Set Username
Figure 7.7: Learning Path Interface
Figure 7.8: Interface with Collapsed Sidebar
Figure 7.9: Chat Interface
Figure 7.10: Video Player Screen
Figure 7.11: Multiple Choice Quiz
Figure 7.12: Code Quiz Interface
Figure 7.13: Quiz Completion Screen
Figure 7.14: Main Dashboard
Figure 7.15: Dashboard Details View
Figure 7.16: Dashboard with Filtration Options
Figure 7.17: Progress & Analysis Dashboard
Figure 7.18: Dark Mode Interface

List of Tables

Table 2.1: Elzero Web School
Table 2.2: Codeforces
Table 2.3: CodeChef
Table 2.4: HackerRank
Table 2.5: LeetCode
Table 2.6: TopCoder
Table 2.7: AtCoder
Table 2.8: CodinGame
Table 2.9: CodeCombat
Table 2.10: Codewars
Table 2.11: CheckiO
Table 3.1: Development and Operational Costs
Table 3.2: Financial Projections
Table 3.3: Technical Risks
Table 3.4: Project Management Risks
Table 3.5: Legal and Compliance Risks
Table 5.1: Actors and Goals List

Chapter 1: Project Overview

1.1 Main Idea

We aim to create a Duolingo-inspired programming education platform that transforms how beginners learn to code by eliminating overwhelm through structured, gamified micro-lessons. Unlike fragmented resources, this platform provides a clear, progressive learning path—from core programming fundamentals to advanced topics like OOP, algorithms, and web development—all delivered via multi-format explanations (articles, videos, and guided walkthroughs).

At its core, the platform seamlessly integrates:

An in-browser code editor (supporting Python and JavaScript) with real-time execution, syntax highlighting, and instant error diagnostics.
Hands-on exercises featuring model solutions and optional complexity analysis to deepen understanding of code efficiency.

XP systems, unlockable levels, daily streaks, and skill badges to reward consistency.
Global leaderboards competitions to fuel engagement.

Visual roadmaps highlighting completed, active, and upcoming modules.
Mastery dashboards quantifying skill growth and retention.

By combining structured curriculum, instant feedback, and social accountability, the platform turns programming education into an addictive, confidence-building journey—making learning feel like play while ensuring tangible skill development.

1.2 Project Scope

1. Comprehensive Curriculum & Content

Structured Learning Path:
- Tiered modules from absolute fundamentals (variables, loops) to advanced domains (OOP, algorithms, web frameworks, databases).
- Specialized tracks for Python, JavaScript, and full-stack development.
Multi-Format Delivery:
- Concept primers: Short videos + annotated articles.
- Interactive Chat Learning: AI mascot chatbot for conversational explanations.

2. Intelligent Code Editor

Multi-Language Support:
- Browser-based execution for Python, JavaScript, HTML/CSS, and more.
Enhanced Developer Experience:
- Real-time syntax + error highlighting, auto-completion, and debugging hints.
Accessibility:
- Dark/light mode, keyboard shortcuts.

3. Dynamic Interactive Exercises

Adaptive Challenges:
- Exercises auto-adjust difficulty based on user performance.
- "Fix-the-Bug" tasks: Debug pre-written flawed code.
Deep-Dive Analysis:
- Runtime complexity breakdowns (Big O notation).
- Memory/performance metrics for optimization practice.
Solution Libraries:
- Model answers + multiple approach comparisons (e.g., iterative vs. recursive).

4. Advanced Gamification System

Engagement Mechanics:
- Daily streaks, skill-specific badges (e.g., "Algorithm Ace"), and XP bonuses for consistency.
- Unlockable content: Secret lessons or tools for high achievers.
Competitive Elements:
- Global/weekly leaderboards (XP-based).

5. Personalized Progress Ecosystem

Learning Analytics:
- Mastery dashboards showing skill proficiency (e.g., "Data Structures: 85%").
- Time-tracking: Session duration, concepts revisited.

6. Accessibility & Scalability

Mobile-responsive design: Seamless tablet/phone access.
Offline mode: Download lessons/exercises for practice without internet.

1.3 Problem Statement

Learning programming remains a daunting barrier for beginners, exacerbated by four core gaps in existing solutions:

Structural Deficiency:
- Resources are fragmented (video tutorials, disjointed exercises) with no coherent progression, leaving learners adrift.
- Advanced topics (OOP, algorithms) feel inaccessible without scaffolded skill-building.
Practice-Explanation Misalignment:
- Passive video/article consumption fails to translate to coding competence.
- Feedback is delayed or absent, leading to reinforcement of errors and frustration.
Motivation Erosion:
- Isolated learning lacks psychological hooks (rewards, social accountability) to sustain consistency.
- 80% of beginners quit within 3 months due to diminishing confidence.

1.4 Solution Approach

To bridge these gaps, the platform leverages Duolingo’s engagement model fused with developer-centric depth:

A. Structured Yet Adaptive Onboarding

Skill Tree Curriculum:
Tiered modules map concepts from syntax basics → real-world stacks (e.g., Flask/React).
Diagnostic quizzes auto-route learners to optimal starting points.
Bite-Sized, Multi-Modal Lessons:
Concepts taught via < 5-min videos, annotated snippets, and interactive sandboxes—all in one flow.

B. Contextual Practice Engine

AI-Assisted Feedback:
 Real-time error explanations + debugging hints (e.g., “Your loop exits early: check conditionals!”). 
Exercise Evolution:
Adaptive difficulty: Problems scale complexity based on user mastery.
Project Sprints: Build portfolio-ready micro-apps (e.g., API-driven weather dashboard).

C. Gamification × Depth

Progressive Unlock System:
Earn XP/badges for accuracy, efficiency (e.g., “O(1) Solver”), and streaks.
Competitive Depth:
Leaderboards rank speed (solved in 30s) vs. elegance (least code lines).
Complexity Playgrounds:
Visualize Big O trade-offs via interactive graph comparisons (e.g., O(n²) vs. O(n log n)).

D. Personalized Reinforcement

Predictive Roadmaps:
Weakness-targeted challenges (e.g., “Struggling with callbacks? Try these 3 exercises!”).
Mastery Analytics:
Heatmaps track concept retention + time-to-proficiency across skills.

1.5 Project Objectives

1. Deliver a Progressive, Mastery-Based Curriculum

Modular Skill Tiers: Implement 10+ competency levels (Novice → Architect) with checkpoint assessments for each tier.
Cross-Language Tracks: Offer specialized paths for Python (Data Science/Backend), JavaScript (Frontend/Full-Stack), and Algorithms.
Real-World Alignment: Integrate industry frameworks (e.g., React, Flask) and tools (Git, APIs) into advanced modules.

2. Build an Intelligent, Adaptive Practice Ecosystem

AI-Driven Exercise Engine:
- Generate personalized problem sets targeting weak areas (e.g., "80% accuracy on recursion? Try these 5 challenges!").
- Auto-graded projects with rubrics for code quality, efficiency, and creativity.
Multi-Layer Feedback:
- Provide instant syntax corrections, runtime error diagnostics, and performance benchmarks (CPU/memory usage).

3. Gamify Learning with Depth & Nuance

Tiered Reward System:
- Award skill-specific badges (e.g., "Memory Optimizer") + rarity tiers (Bronze → Platinum).
- "Double-or-Quit" streaks: Bonus XP for consecutive days, reset on skip.
Competitive Arenas:
- Host weekly efficiency leagues (lowest Big O wins) and speed sprints (fastest debugger).

4. Enable Hyper-Personalized Tracking

Predictive Analytics Dashboard:
- Visualize skill decay (e.g., "Arrays mastery ↓15% in 2 weeks") and recommend refreshers.
- Track efficiency gains (e.g., "Reduced solution time by 40% this month").
Custom Roadmapping:
- Let users build goal-oriented playlists ("Prep for FAANG Interviews" → auto-adds relevant exercises).

5. Ensure Accessibility & Scalability

Inclusive Design:
- Support screen readers, keyboard navigation, and color-blind modes.
- Offer text-to-speech explanations for complex concepts.
Infrastructure Goals:
- Offline-first capability: Download modules + editor for remote learning.
- API extensibility: Integrate with GitHub/LMS platforms for portfolio syncing.
By achieving these objectives, the platform will not only demystify programming for beginners but also cultivate a motivated, skilled community ready to tackle real-world coding challenges.

Chapter 2: Project Background

2.1 Project Background

Figma is a versatile, cloud‑based design platform widely used for crafting user interfaces, wireframes, and interactive prototypes. It enables designers and stakeholders to collaborate in real time, streamlining the design process from ideation to final output. Figma’s rich feature set — including vector editing, component‑based design, version history, and a robust plugin ecosystem — makes it central to modern UI/UX workflows. As a browser‑based tool, it removes installation barriers and ensures cross‑device accessibility.

For more detailed imformation. you can refer to Figma.

Nuxt.js is a high-level framework built on Vue.js, optimized for developing server-rendered applications and static websites. It offers features like automatic routing, server-side rendering (SSR), static site generation, and a modular architecture. With built-in support for SEO, performance optimizations, and a rich community-driven ecosystem, Nuxt simplifies the development of scalable, high‑performance web apps.

For more detailed imformation. you can refer to Nuxt.js.

.NET is a powerful, open-source development platform created by Microsoft for building modern, scalable, and high-performance applications. It supports multiple languages such as C#, F#, and VB.NET, and enables developers to create applications across web, desktop, mobile, cloud, and IoT environments. Known for its strong type system, robust security features, and extensive class libraries, .NET streamlines development while ensuring reliability and maintainability. With the introduction of .NET Core and now .NET 8, it offers cross-platform support and exceptional performance.

For more detailed information, you can refer to .NET.

Microsoft SQL Server is a robust, enterprise-grade relational database management system (RDBMS) developed by Microsoft. It is designed to store, manage, and retrieve data efficiently while ensuring high performance, security, and reliability. SQL Server supports both structured query language (SQL) for relational data and JSON for semi-structured data, making it suitable for diverse modern applications. It offers advanced features such as ACID compliance, indexing, views, triggers, stored procedures, and built-in analytics through SQL Server Analysis Services (SSAS). With strong support for scalability, data integrity, and transaction management, SQL Server is widely used in enterprise environments for web applications, business intelligence, and large-scale data solutions.

For more detailed information, you can refer to Microsoft SQL Server.

OpenRouter is an open‑source API platform that offers a unified interface to multiple large language models (LLMs). It enables developers to seamlessly integrate AI features—such as natural language processing, chat interfaces, and content generation—while managing authentication, fallback strategies, and cost efficiency. OpenRouter simplifies switching between or combining models from different providers.

For more detailed imformation. you can refer to OpenRouter.

Gemini API is a developer-friendly interface provided by Google to access the capabilities of its Gemini family of large language models (LLMs). It allows developers to integrate advanced AI features into their applications, including natural language understanding, code generation, content summarization, and multi-modal reasoning (text, image, and more). The Gemini API is accessible through Google AI Studio and is designed to support rapid prototyping and scalable deployment of generative AI solutions. With robust security, comprehensive documentation, and seamless integration with Google Cloud, the Gemini API enables powerful, flexible AI experiences across a wide range of use cases.

For more detailed imformation. you can refer to Gemini API documentation.

Monaco Editor is the highly customizable, in‑browser code editor that powers Visual Studio Code. It supports syntax highlighting, IntelliSense, code folding, and more. Lightweight yet powerful, Monaco is perfect for embedding code editing experiences within web applications such as educational platforms, developer tools, or live coding playgrounds.

For more detailed imformation. you can refer to Monaco Editor.

Cloudflare is a leading web performance and security platform that provides a wide range of services to protect and accelerate websites, APIs, and applications. It acts as a reverse proxy between users and web servers, offering features such as DDoS protection, content delivery network (CDN), SSL/TLS encryption, firewall rules, and performance optimization. By caching content at global edge locations and filtering malicious traffic, Cloudflare helps improve loading speeds, reduce server load, and enhance overall security. It also offers developer tools like Cloudflare Pages and Workers for deploying scalable, serverless applications.

For more detailed imformation. you can refer to: CloudFlare.

Elzero Web School

Description	Techniques Used	Advantages	Disadvantages
Elzero Web School is an excellent free resource for Arabic-speaking beginners and intermediate learners who want to build strong web development skills through structured, practical learning.	- External resources and useful tool recommendations included - A Q&A section to ask questions and receive community support	- Step-by-step structured study plans for better learning flow - Dedicated learning paths for Frontend, Backend, and Full Stack	- No built-in progress tracking to monitor course completion - Users cannot rate or review courses or lessons

Reference: https://elzero.org

Codeforces

Description	Techniques Used	Advantages	Disadvantages
A well-known platform that hosts regular contests like Div 1 and Div 2. It includes a robust rating system and editorial support to develop algorithmic thinking.	- Mathematical algorithms - Rating system - Editorial learning	- Regular contests with large community participation - Detailed editorial explanations - Transparent and active rating system	- Interface can be intimidating for beginners - Problems often require deep mathematical insight

Reference: https://codeforces.com

CodeChef

Description	Techniques Used	Advantages	Disadvantages
An Indian educational platform hosting contests like Long Challenge and Lunchtime, with a vast problem archive and community engagement.	- Long format contests (Long Challenge) - Short contests (Lunchtime) - Tutorial-based learning	- Great for long-term learning with multiple contest formats - Offers tutorials and mentorship programs	- Sometimes suffers from server lags during contests - Problems can be less curated compared to Codeforces or LeetCode

Reference: https://www.codechef.com

HackerRank

Description	Techniques Used	Advantages	Disadvantages
Focuses on algorithms, SQL, and data structures with a live coding environment, widely used for tech interviews.	- Structured learning paths - Auto-grading system - Skill-specific tracks (SQL, AI, etc.) - Live coding interface	- Beginner-friendly interface and structured learning paths - Great for practicing specific skills (e.g. SQL, AI) - Instant feedback and auto-grading	- Contest competitiveness is relatively low - Less challenging for advanced users

Reference: https://www.hackerrank.com

LeetCode

Description	Techniques Used	Advantages	Disadvantages
A premier platform for coding interview prep with 2,500+ problems and company-specific questions.	- Interview prep questions - Company-tagged problems - Weekly contests - Solution discussions	- Focused on technical interview preparation - Community solutions and tutorials - Weekly contests to benchmark skills	- Some premium features are behind a paywall - Less emphasis on advanced algorithms

Reference: https://leetcode.com

TopCoder

Description	Techniques Used	Advantages	Disadvantages
One of the oldest platforms, known for SRM (Single Round Matches) and Marathon Matches focusing on complex, long-term problems.	- SRM (Single Round Match) - Marathon Match - High-difficulty algorithm challenges - Real-world modeling problems	- Highly competitive and professional-grade problems - Real-world challenges and big prizes - Community of expert coders	- Interface feels outdated - Steeper learning curve for newcomers

Reference: https://www.topcoder.com

AtCoder

Description	Techniques Used	Advantages	Disadvantages
A Japanese platform offering well-structured contests (ABC, ARC, AGC) with a focus on clean problem statements and difficulty progression.	- ABC, ARC, AGC contests - Clean and structured problems - Difficulty progression - On-time weekly contests	- High-quality problems and fair difficulty curve - Regular, punctual contests - Structured for serious learners	- Japanese-first interface; some translations may be rough - Smaller international community than others

Reference: https://atcoder.jp

CodinGame

Description	Techniques Used	Advantages	Disadvantages
Gamifies coding challenges with multiplayer and story-based games like Clash of Code and Code vs Zombies.	- Game-based problem solving - Real-time multiplayer coding - Visual programming challenges - Language flexibility (25+)	- Fun and visual way to learn coding - Supports 25+ programming languages - Great for casual or team play	- Not focused on algorithm depth - Less suitable for serious competitive programming

Reference: https://www.codingame.com

CodeCombat

Description	Techniques Used	Advantages	Disadvantages
An RPG-style platform that teaches Python, JavaScript, and HTML through story-driven games and challenges.	- RPG-style game interface - Code-to-play mechanics - Curriculum-based learning - Beginner visual feedback	- Ideal for children and beginners - Game-based engagement with rewards - Offers structured curriculum	- Too basic for experienced developers - Some content requires a subscription

Reference: https://codecombat.com

Codewars

Description	Techniques Used	Advantages	Disadvantages
Uses "Kata" - short coding exercises - to improve coding progressively with ranking and community feedback.	- Community challenge creation - Rank-based progression - Peer-reviewed solutions	- Unique ranking and progression system - Community-driven challenges and solutions - Good for practicing idiomatic code	- Lacks formal contest system - Quality of community challenges can vary

Reference: https://www.codewars.com

CheckiO

Description	Techniques Used	Advantages	Disadvantages
Offers gamified learning of Python and JavaScript through short, interactive problem-solving challenges.	- Gamified challenges - Code review mechanism - Puzzle solving - Interactive feedback	- Fun and visual interface - Encourages reviewing others' code - Python-focused challenges are especially polished	- Less suitable for advanced algorithm training - Limited language support

Reference: https://checkio.org

2.3 Summary

In this chapter, the tools that will be used in implementation like (Node.js, Nuxt.js, Figma, Gemini API, OpenRouter, Monaco Editor, and CloudFlare). were described. Then the related work was described, (Which is listed in the previous table), and the advantages, disadvantages, and benefits of each one, then compared with the project.

Chapter 3: Feasibility and Project Planning

3.1 Feasibility Study

3.1.1 Technical Feasibility

Familiarity with Applications:
- The target learners and educators in our region are already familiar with mobile educational apps and interactive tutorials (e.g. Duolingo, Code.org) in Arabic. Using a gamified, Arabic-language interface makes the platform intuitive; users require no extra training to log in, practice coding, or track progress.
- Core team members have experience building web/mobile learning tools, so we understand typical user workflows (account setup, interactive lessons).
- Because the UI and content are in Arabic, language barriers are eliminated, further smoothing the learning curve for beginners.
Familiarity with Technology:
- Our team has strong expertise in the chosen tech stack: we have built Vue/Nuxt.js and .NET applications before and are proficient with SQL Server databases. This means we can efficiently develop the front-end UI and the back-end server.
- We have experience with embedding real-time code editors (the platform will use Microsoft’s Monaco Editor, the same engine as VS Code) and handling Python and JavaScript code execution on the server.
- We are comfortable working with AI APIs; in past projects we have integrated services (e.g. OpenAI APIs) and we can similarly use OpenRouter to connect to the Gemini API for intelligent hints. Overall, our familiarity is high and we have confidence that we have the coding, design, and integration skills needed to implement all planned features.
Project Size:
- The core team will include about 6 members (detailed below), which is appropriate for a mid-size project.
- The platform’s scope involves a moderate variety of features: a real-time code editor (supporting Python and JS), gamification mechanics (XP, badges, streaks, daily goals), AI-driven hints. This is a mid-level complexity for an experienced team.
- The development timeline is relatively tight: with a target launch by May 2026 (about 6 months from planning start), the schedule is ambitious. However, by assigning parallel sprints for front-end, back-end, and content creation, and by leveraging reusable components (Nuxt/Vue libraries, Monaco Editor, etc.), we believe the team can meet this deadline.

3.1.2 Organizational Feasibility

Project Advisor: Dr. Rehab Emad El-Dein
Champion: The development team and supervisors provide time and effort for the system.
System Users:
1. Learners: Arabic-speaking students and self-learners who use the platform to learn programming through structured courses, interactive exercises, and real-time code challenges. They earn XP, badges, and streaks as they progress.
2. Mentors/Instructors: More experienced developers or educators who contribute by answering questions, reviewing user code, curating content, and moderating the community. Mentors help ensure quality and provide additional support (similar to Duolingo “language mentors”).
3. Administrators/Content Creators: A small team of admins who upload new course material, monitor the system, and handle technical support.
Development Team Breakdown: The team is organized into specialized roles with overlapping collaboration to ensure flexibility:
- Back-end Developers (2):
  Build and maintain the server-side logic in .NET, manage the SQL Server database, and implement APIs. One of the back-end developers will also take on DevOps responsibilities, handling cloud infrastructure, CI/CD pipelines, and security. Together, they will also implement real-time code execution and integration with AI APIs.
- Front-end Developers (2):
  Develop the user interface using Nuxt.js, ensuring a responsive and intuitive design across desktop and mobile browsers. They will integrate the Monaco editor, implement gamification features (XP, badges, leaderboards), and collaborate closely with the mobile developer to keep design consistent.
- Mobile Developer (1):
  Focuses on building and optimizing the mobile application version of the platform, ensuring a smooth experience on iOS and Android. Works with front-end and back-end teams for synchronization and performance.
- AI Engineer (1):
  Specializes in integrating AI features, including intelligent hints and personalized feedback, through APIs like OpenRouter/Gemini. This role also explores adaptive learning models to tailor exercises to each learner’s progress.
- Content & Instructional Design (shared responsibility):
  Instead of dedicated content creators, all team members will collaborate on producing and localizing course material in Arabic. This includes designing structured lessons, writing exercises, and embedding gamification mechanics. Team members’ technical expertise ensures content is accurate, while shared responsibility distributes workload evenly.

3.1.3 Economic Feasibility

Tangible Benefits:
- Course Revenue: With a pay-per-course model at an average price of $30 per course, enrolling 5,000 users in Year 1 (our target) would generate roughly $150,000 in Year-1 sales. As user growth continues, Year 2 and 3 revenues could be, for example, $225,000 and $300,000 (assuming 50% year-over-year user growth).
- Additional Revenue Streams: We can develop premium content or certification services in later years (e.g. advanced courses, official completion certificates) to create new revenue. Partnerships or bulk licenses with schools or companies could also add income.
- Economies of Scale: Because hosting and maintenance costs (see below) are largely fixed per year, each additional user above Year 1 yields mostly profit. For instance, once we cover the $20,000/year hosting expense and $50,000/year marketing, further enrollments significantly improve margins.
Intangible Benefits:
- Learner Engagement: The gamified, Duolingo-style approach will keep students motivated. Studies show gamification (points, streaks, badges) significantly boosts user engagement and retention. By making coding fun and rewarding, we help learners persist.
- Education Impact: Providing coding education in Arabic removes language barriers and makes computer science more accessible. This can broaden participation in tech education and help develop local talent in programming.
- Brand and Market Position: Successfully launching this platform will position our team as innovators in Arabic EdTech. Positive reputation and user testimonials will attract future investments, partnerships, and possibly expansion into new topics or markets.

Development and Operational Costs (Years 0–3):

Item	Year 0	Year 1	Year 2	Year 3	Total
Development (one-time)	$280,000	$0	$0	$0	$280,000
Dev team salaries	$180,000	–	–	–	$180,000
Content creation	$100,000	–	–	–	$100,000
Hosting/AI/maint.	$0	$20,000	$20,000	$20,000	$60,000
Marketing	$0	$50,000	$50,000	$50,000	$150,000
Total Cost	$280,000	$70,000	$70,000	$70,000	$490,000

ROI and Cumulative Net:

Metric	Year 0	Year 1	Year 2	Year 3	Total
Revenue	$0	$150,000	$225,000	$300,000	$675,000
Total Cost	$280,000	$70,000	$70,000	$70,000	$490,000
Net Profit	-$280,000	$80,000	$155,000	$230,000	$185,000
Cumulative Net	-$280,000	-$200,000	-$45,000	$185,000	—

3-Year ROI: $185,000 ÷ $490,000 ≈ 37.8%

Break-even Analysis

The break-even point occurs when cumulative revenue surpasses cumulative costs:

Year 1: Cumulative revenue = $150,000, cumulative cost = $350,000 → still negative (-$200,000).
Year 2: Cumulative revenue = $375,000, cumulative cost = $420,000 → still negative (-$45,000).
Year 3: Cumulative revenue = $675,000, cumulative cost = $490,000 → positive cumulative net ($185,000).

Therefore, the project is expected to break even during Year 3, after which all additional revenue contributes to profit.

To illustrate:

Break-even revenue threshold: $490,000 (total 3-year cost).
Achieved at ~16,333 paid enrollments (490,000 ÷ $30).
Based on projected growth, this milestone will be reached in the third year of operation.

Figure 3.3: Cumulative Revenue vs Cumulative Cost - Chart showing break-even point analysis over a 3-year period — Figure 3.3: Cumulative Revenue vs Cumulative Cost

3.2 Risk Management

This section identifies key risks for the coding education platform across technical, operational, and legal domains. Each risk is assessed with a likelihood (Low/Medium/High), impact (Low/Medium/High), and mitigation strategies. Where appropriate, a qualitative risk matrix is used to emphasize prioritization.

3.2.1 Technical Risks

Risk	Description	Likelihood	Impact	Mitigation
Scalability & Uptime	High traffic or data growth could overwhelm the platform. Without modular architecture and robust testing, performance bottlenecks and downtime can occur.	High	High	Design a scalable, microservices-based architecture; use horizontal scaling (load balancing, CDN, caching); implement automated testing and monitoring to detect and prevent bottlenecks.
External API Integration	Reliance on third-party APIs (e.g. Gemini, OpenRouter) can introduce outages or unpredictable behavior. Third-party services may have downtime or breaking changes.	Medium	High	Vet and monitor external APIs closely (uptime/SLA checks); implement timeouts and retries; use circuit breakers to protect against surges; prepare fallback or degraded modes if an API fails.
Real-time Code Execution	Running user-submitted code in real time is error-prone. Sandbox failures, resource exhaustion, or vulnerabilities could crash the executor, harming reliability.	Medium	High	Isolate execution in secure sandboxes or containers; enforce resource limits (memory/time); continuously test with diverse workloads; scale the execution engine separately; monitor and auto-recover.

3.2.2 Operational Risks

Risk	Description	Likelihood	Impact	Mitigation
Timeline Delays	Requirement changes, scope creep, or underestimation can derail schedules. Over-optimistic estimates may lead to extended deadlines.	High	High	Use thorough upfront planning and clear requirements; apply realistic time estimates with contingency; use agile sprints for incremental delivery and reviews.
Resource Constraints	Limited team size or skill shortages create bottlenecks.	Medium	High	Cross-train staff and onboard talent early; use contingent resources; maintain a pipeline of developers; forecast and reallocate workloads proactively.
Content Development Bottlenecks	Creating high-quality, engaging coding lessons and exercises is time-consuming, which can delay releases or reduce quality.	Medium	Medium	Develop content iteratively with SMEs; reuse or adapt existing materials; employ instructional designers; prioritize high-impact modules first.

3.2.3 Legal & Compliance Risks

Risk	Description	Likelihood	Impact	Mitigation
Data Privacy (Minors)	Collecting data on children raises strict legal requirements (e.g., COPPA, GDPR). Failure to comply can cause severe penalties.	Medium	High	Apply "privacy by design": minimize data collection, encrypt sensitive data, obtain parental consent, maintain clear privacy policies, and conduct regular audits.
Copyright & Licensing	Using third-party or community code/assets risks license infringement. Even one noncompliant license could result in legal or financial penalties.	Low	Medium	Enforce strict review of all content/code; use license scanners; prefer permissive or original content; educate users on plagiarism; remediate infringing material.
Terms-of-Service Violations	Users may post disallowed content (hate speech, copyrighted code, malicious submissions) or cheat, violating the platform's ToS.	Medium	Medium	Publish comprehensive ToS; implement moderation and reporting tools; enforce rules via filters and manual review; respond promptly and revise policies regularly.

3.3 Project plan

TO DO

3.4 Gantt Chart

TO DO

Chapter 4: System Analysis

4.1 Function Requireements

4.1.1 User Management System

User Registration and Authentication

FR-1.1: System shall allow users to create accounts using email, username, and password.
FR-1.2: System shall support social login (Google, GitHub) for quick registration.
FR-1.3: System shall implement email verification for new accounts.
FR-1.4: System shall provide secure password reset functionality via email.
FR-1.5: System shall enforce strong password policies (minimum 8 characters, special characters).
FR-1.6: System shall implement two-factor authentication (2FA) as an additional security feature.

Optional Feature: Two-factor authentication (2FA).

User Profiles and Settings

FR-1.7: System shall allow users to create and edit personal profiles with avatar, bio, and learning goals.
FR-1.8: System shall allow users to select preferred programming languages (Python, JavaScript, etc.).
FR-1.9: System shall support multiple language interface options (Arabic, English).

Optional Feature: Language interface options.

User Roles and Permissions

FR-1.10: System shall support multiple user roles: Learner, Administrator, Content Creator.
FR-1.11: System shall implement role-based access control for different platform features.

4.1.2 Learning Management System

Course Structure and Navigation

FR-2.1: System shall organize content into structured learning paths from fundamentals to advanced topics.
FR-2.2: System shall implement prerequisite-based lesson unlocking mechanisms.
FR-2.3: System shall provide a visual learning roadmap showing completed, current, and locked modules.
FR-2.4: System shall support multiple learning tracks (Python, JavaScript, Web Development, OOP, Algorithms).

Optional Feature: Lesson bookmarking.

Lesson Content Delivery

FR-2.5: System shall support multi-format lesson content (text, videos, interactive demos).
FR-2.6: System shall provide step-by-step coding walkthroughs with highlighted code segments.
FR-2.7: System shall include conceptual explanations before practical exercises.
FR-2.8: System shall support rich text formatting, code syntax highlighting, and embedded media.

Optional Feature: Estimated completion time per lesson.

Adaptive Learning Features

FR-2.9: System shall track user performance and recommend personalized learning paths.
FR-2.10: System shall adjust exercise difficulty based on user success rates.
FR-2.11: System shall provide spaced repetition reminders for previously learned concepts.

4.1.3 Code Editor and Execution Environment

In-Browser Code Editor

FR-3.1: System shall embed Monaco Editor for in-browser code editing.
FR-3.2: System shall support syntax highlighting for Python, JavaScript, etc.
FR-3.3: System shall provide auto-completion and IntelliSense features.
FR-3.4: System shall include line numbering, code folding, and bracket matching.
FR-3.5: System shall support multiple editor themes (dark/light mode).
FR-3.6: System shall provide keyboard shortcuts for common coding operations.

Code Execution and Testing

FR-3.7: System shall execute user code securely using APIs.
FR-3.8: System shall display real-time output and error messages.

Optional Feature: Test case validation, execution performance metrics.

Code Analysis and Feedback

FR-3.9: System shall provide instant syntax error detection and suggestions.
FR-3.10: System shall offer code optimization suggestions and best practices.
FR-3.11: System shall compare user solutions with model answers.
FR-3.12: System shall highlight potential bugs or logical errors using LLM.

Optional Feature: Code complexity analysis with Big O insights.

Blockly Integration

FR-3.13: System shall provide a block-based workspace with customizable categories (Logic, Math, Control, Events, etc.).
FR-3.14: System shall allow users to generate source code (JavaScript/Python) from block structures.
FR-3.15: System shall enable code execution within the application environment.
FR-3.16: System shall support saving and loading block configurations in XML/JSON format.

Optional Feature: Custom block expansion.

4.1.4 Interactive Exercise System

Exercise Types and Structure

FR-4.1: System shall support coding challenges, bug fixing, code completion, and multiple-choice exercises.
FR-4.2: System shall provide clear problem statements with input/output examples.
FR-4.3: System shall include starter code templates when appropriate.
FR-4.4: System shall support progressive difficulty within exercise sets.
FR-4.5: System shall offer optional hints and explanations.

Validation and Grading

FR-4.6: System shall automatically validate solutions against test cases.
FR-4.7: System shall track solution attempts and provide retry mechanisms.

Optional Feature: Immediate feedback, partial credit.

Solution Management

FR-4.8: System shall provide "section of solutions" after successful completion.
FR-4.9: System shall allow users to submit multiple approaches to the same problem.

Optional Feature: Save and version solutions.

4.1.5 Gamification System

Points and Experience (XP)

FR-5.1: System shall award XP for completed lessons, exercises, and achievements.
FR-5.2: System shall implement progressive XP requirements for level advancement.
FR-5.3: System shall provide XP bonuses for consecutive learning streaks.
FR-5.4: System shall award bonus points for first attempts.
FR-5.5: System shall display XP progress bars and level indicators.

Achievement System

FR-5.6: System shall implement badge categories (completion, mastery, collaboration).
FR-5.7: System shall provide rare and legendary badges for exceptional achievements.
FR-5.8: System shall display badge galleries on user profiles.
FR-5.9: System shall notify users upon earning new achievements.

Optional Feature: Skill-specific badges.

Leaderboards and Competition

FR-5.10: System shall maintain global and weekly leaderboards.
FR-5.11: System shall support friend-based leaderboards and challenges.
FR-5.12: System shall provide leaderboard filtering by time, skill level, or language.

Streaks and Daily Goals

FR-5.13: System shall track daily learning streaks with visual indicators.
FR-5.14: System shall send streak reminder notifications.
FR-5.15: System shall provide streak recovery options.

Optional Feature: Personalized daily goals.

Certification Management

FR-5.16: System shall display all available certifications with details.
FR-5.17: System shall allow eligible users to enroll in certification tracks.
FR-5.18: System shall create a certification dashboard showing progress and deadlines.

4.1.6 Progress Tracking and Analytics

Individual Progress Monitoring

FR-6.1: System shall maintain comprehensive learning history per user.
FR-6.2: System shall calculate and display skill mastery percentages.
FR-6.3: System shall track time spent on topics and exercises.
FR-6.4: System shall identify strengths and weaknesses.

Performance Analytics

FR-6.5: System shall track accuracy rates and improvement trends.
FR-6.6: System shall monitor learning velocity.
FR-6.7: System shall calculate estimated completion time for coursework.

Visual Progress Representation

FR-6.8: System shall provide interactive progress roadmaps.
FR-6.9: System shall display skill trees showing mastered and locked concepts.

Optional Feature: Charts and graphs for analytics.

4.1.7 AI-Powered Features

Intelligent Hints and Assistance

FR-7.1: System shall integrate AI APIs (Gemini via OpenRouter) for contextual hints.
FR-7.2: System shall provide progressive hint levels.
FR-7.3: System shall analyze user code and suggest improvements.
FR-7.4: System shall generate explanations for complex programming concepts.
FR-7.5: System shall adapt hint complexity based on user skill.

Personalized Learning Recommendations

FR-7.6: System shall suggest relevant exercises when users struggle.

Optional Feature: Learning schedules, AI practice problems.

Automated Content Generation

FR-7.7: System shall generate variations of exercises for extra practice.
FR-7.8: System shall generate code examples for abstract concepts.

4.1.8 Content Management System

Course and Lesson Administration

FR-8.1: System shall provide a content creation interface for authorized users.

Optional Feature: Content scheduling, review workflows.

Exercise and Assessment Management

FR-8.2: System shall allow creation of coding exercises with test cases.
FR-8.3: System shall support exercise difficulty categorization.
FR-8.4: System shall validate exercises before publication.

Optional Feature: Exercise cloning and templates.

Multimedia Content Support

FR-8.5: System shall support video upload or embedding.
FR-8.6: System shall support content localization for multiple languages.

Optional Feature: Image embedding and interactive content creation.

4.1.9 System Administration

User Management

FR-9.1: System shall provide an administrative dashboard for managing user accounts.
FR-9.2: System shall support user role assignment and permission management.

Platform Monitoring and Analytics

FR-9.3: System shall maintain system logs and audit trails.
FR-9.4: System shall provide usage statistics and dashboards.

Content Moderation

FR-9.5: System shall support manual content review and moderation workflows.
FR-9.6: System shall maintain content removal and user warning systems.

4.1.10 Integration and API Features

Third-Party Integrations

FR-10.1: System shall integrate with external authentication providers (OAuth or BetterAuth).
FR-10.2: System shall connect with AI services (OpenRouter, Gemini API).

Platform APIs

FR-10.3: System shall provide RESTful APIs for web and mobile apps.
FR-10.4: System shall support webhook integrations.

Mobile and Cross-Platform Support

FR-10.5: System shall deliver a responsive web interface optimized for mobile.
FR-10.6: System shall provide mobile-specific features (push notifications).
FR-10.7: System shall ensure cross-browser compatibility.

Optional Feature: Offline content caching.

4.1.11 Security and Privacy

Data Protection

FR-11.1: System shall encrypt sensitive user data at rest and in transit.
FR-11.2: System shall implement secure session management and timeouts.
FR-11.3: System shall provide privacy controls and data deletion options.
FR-11.4: System shall comply with GDPR and COPPA standards.

Platform Security

FR-11.5: System shall implement input validation and sanitization.
FR-11.6: System shall protect against XSS, CSRF, and SQL injection.
FR-11.7: System shall secure API endpoints with authentication and authorization.
FR-11.8: System shall implement rate limiting and DDoS protection.

4.2 Non-Function Requirements

4.2.1 Performance

NFR-1.1: Response Time

Landing page load: 2 seconds (3G or better)
Monaco editor initialization: 3 seconds
Code execution results: 5 seconds (standard exercises)
API responses: 1 second (login, save, submit)
Search/filtering: 2 seconds

NFR-1.2: Throughput

Concurrent users: 1,000+ without degradation
Simultaneous code executions: 500+
Peak submissions: 10,000/hour

NFR-1.3: Resource Utilization

Client memory: ≤ 500MB
Monaco editor: ≤ 200MB
Database queries: 100ms (95% of operations)
CDN cache hit rate: 90%+

NFR-1.4: Rendering Performance

Interactive elements response: 100ms
Animation frame rate: 60 FPS
Roadmap rendering (100 nodes): 1.5 seconds

4.2.2 Availability

NFR-2.1: System Uptime

Annual uptime: 99.5% (~43.8 hours downtime)
Maintenance windows: ≤ 4 hours/month (low-usage periods)

NFR-2.2: Service Availability

Core features: 24/7 availability
AI hints: 95% uptime
Leaderboards: 98% uptime

NFR-2.3: Geographic Availability

Global accessibility with focus on Arabic-speaking regions

NFR-2.4: Graceful Degradation

AI unavailable → pre-generated hints available
Execution service down → lessons & content accessible

4.2.3 Scalability

NFR-3.1: Horizontal Scalability

Stateless architecture for seamless load balancing
Connection pooling for efficient resource management

NFR-3.2: User Growth

Year 1: 50,000 users
Year 3: 200,000 users (without major changes)

NFR-3.3: Content Scalability

Launch: 500 lessons, 5,000 exercises
Future: 2,000 lessons, 20,000 exercises
Support new languages without refactoring

NFR-3.4: Database Scalability

PostgreSQL with read replicas
Quarterly query plan reviews

4.2.4 Reliability

NFR-4.1: Error Rate

System error rate: &lt0.5%
Code execution failures: &lt1% (system errors only)

NFR-4.2: Data Integrity

ACID compliance for progress data (Atomicity, Consistency, Isolation, Durability)
Daily backups with 30-day point-in-time recovery

NFR-4.3: Fault Tolerance

No single point of failure
Database failover: 60 seconds automatic

NFR-4.4: Data Consistency

Leaderboards: eventual consistency within 5 minutes
User profiles: immediate consistency
Cache invalidation: 30 seconds

4.2.5 Interoperability

NFR-5.1: API Standards

RESTful design with standard HTTP methods
JSON responses with consistent structure
OpenAPI/Swagger documentation

NFR-5.2: Third-Party Integration

OAuth 2.0 (Google, GitHub)
Webhook support with JSON payloads

NFR-5.3: Data Exchange

Export formats: JSON, CSV
Version-control compatible storage

NFR-5.4: Browser Compatibility

Chrome, Firefox, Safari, Edge (latest versions)
Browsers released within 2 years

NFR-5.5: Mobile Compatibility

Responsive: 320px–2560px
Native notifications (FCM/APNs)

4.2.6 Usability

NFR-6.1: Learnability

Account setup → first lesson: 5 minutes
Interactive tutorial: &lt10 minutes

NFR-6.2: UI Design

Material Design principles
Arabic (RTL) and English (LTR) support
3 font size options

NFR-6.3: Accessibility

Keyboard navigation (tab, arrows, enter)
ARIA labels and semantic HTML
Color-blind modes with alternative indicators

NFR-6.4: Error Handling

User-friendly messages (Arabic/English)
Contextual help tooltips
Searchable help center accessible from all pages

NFR-6.5: Localization

Full Arabic/English localization
Language switching without progress loss
Regional date, time, and number formatting

NFR-6.6: Responsiveness

Immediate visual feedback
Progress indicators for operations > 1 second

4.2.7 Maintainability

NFR-7.1: Code Quality

Test coverage: ≥ 80% (critical components)
Peer review required before merge

NFR-7.2: Documentation

API docs with examples and schemas
Architecture diagrams (system, database, data flow)
Code comments for complex logic

NFR-7.3: Modularity

Reusable, independently testable components
Versioned migration scripts

NFR-7.4: Logging & Monitoring

Centralized logs with 90-day retention
Automated alerts for critical errors

NFR-7.5: Deployment

Automated CI/CD pipelines
Rollback capability: 10 minutes

4.2.8 Recovery

NFR-8.1: Backup & Restore

Daily full + 6-hour incremental backups
30-day point-in-time recovery
Weekly integrity verification

NFR-8.2: Disaster Recovery

Semi-annual testing
RTO: 4 hours
RPO: ≤ 1 hour data loss

NFR-8.3: Failure Detection

Alert within 2 minutes of critical failure

NFR-8.4: Data Recovery

Individual account restoration
Checksum validation with automatic rollback

NFR-8.5: Service Recovery

Resume after maintenance: 5 minutes
Automatic session restoration
Clear incident messaging

NFR-8.6: Transaction Recovery

Automatic completion or manual review
Transaction log maintenance

4.3 Functional Decomposition

Decomposition Diagram - Part 1

Decomposition Diagram - Part 2

Chapter 5: System Architecture

5.1 Actor-goal List

Actor	Goals
Learner	1. Register, log in, and manage their own profiles. 2. Choose preferred programming languages and interface languages. 3. Follow structured learning paths and unlock lessons progressively. 4. Learn via text, videos, and interactive demos. 5. Practice coding using Monaco Editor with syntax highlighting, auto-completion, and real-time feedback. 6. Receive AI-powered hints, explanations, and recommendations. 7. Complete exercises, earn XP, badges, and certifications. 8. Track progress, mastery, and performance analytics. 9. Participate in leaderboards, streaks, and challenges.
Content Creator / Instructor	1. Create and manage courses, lessons, and coding exercises. 2. Categorize exercises by difficulty and validate before publishing. 3. Add multimedia (videos, images) and localized content. 4. Review and update educational materials. 5. Generate content in different formats (text, code, interactive demos).
Administrator	1. Manage user accounts and assign roles/permissions. 2. Monitor platform analytics and logs. 3. Moderate content and enforce warnings or removals. 4. Oversee data security, backups, and system performance. "-" 5. Configure integrations and APIs for external services. "-"
AI System (Gemini / OpenRouter)	1. Provide contextual hints and adaptive learning recommendations. 2. Analyze learner code to detect errors and suggest improvements. 3. Generate additional exercises and code examples. "-" 4. Adjust hint complexity based on user skill level. "-"

5.2 Use Cases Diagram

5.3 Use Cases Format

This section presents use cases for the DuoCodo platform organized by user role. The cases progress from administrative functions through content creation to learner interactions, using three format levels: Brief (one-line), Casual (structured scenarios), and Fully Dressed (comprehensive specifications).

5.3.1 Administrator Use Cases

Brief Format Use Cases

1. View System Logs

The administrator views system activity logs, error reports, and security events to monitor platform health.

2. Check Platform Statistics

The administrator views key metrics including total users, active learners, course enrollments, and system performance indicators.

3. View User List

The administrator displays a searchable list of all registered users with basic information and account status.

Casual Format Use Cases

4. Manage User Accounts

Actor

Administrator

Main Success Scenario

The administrator logs into the admin dashboard.

The administrator navigates to the "User Management" section.

The system displays a searchable, filterable user list with columns:

Username

Role (Learner/Content Creator/Admin)

Account status (Active/Suspended/Deactivated)

Registration date

Last login

Total XP/Activity level

The administrator can search by username, email, or user ID.

The administrator can filter by:

Role type

Account status

Registration date range

Activity level (active/inactive)

The administrator selects a specific user to view details.

The system displays comprehensive user profile:

Personal information

Enrolled courses

Progress statistics

Activity history

Violation reports (if any)

The administrator can perform actions:

Edit user information

Reset password

Change account status

Adjust user role

View security logs

The administrator makes necessary changes and clicks "Save."

The system updates user information and logs the administrative action.

The affected user receives notification of account changes (if applicable).

Alternative Scenarios

A1. User Not Found

At Step 4, if search returns no results:

"No users found matching '[search term]'. Try different keywords or check spelling."

A2. Concurrent Admin Actions

At Step 9, if another admin is editing the same user:

"Administrator [Name] is currently editing this account. Changes may conflict."

System prevents conflicting simultaneous edits.

A3. Cannot Modify Super Admin

At Step 8, if attempting to change super admin permissions:

"Super Administrator accounts cannot be modified. Contact platform owner for changes."

A4. Bulk Action Requested

At Step 8, if admin selects multiple users:

The system offers bulk actions: suspend, send message, export data

Admin confirms bulk action

System processes with progress indicator

5. Assign User Roles

Actor

Administrator

Main Success Scenario

The administrator navigates to "Role Management" in the admin panel.

The system displays available roles:

Learner (default)

Content Creator

Mentor/Reviewer

Administrator

Super Administrator

The administrator searches for a specific user.

The administrator selects the user and clicks "Change Role."

The system displays current role and available role options.

The administrator selects the new role from the dropdown.

If promoting to Content Creator or higher, the system prompts:

"This role grants elevated permissions. Confirm you want to proceed?"

The administrator confirms the role change.

The system updates the user's role and permissions.

The system sends notification to the user:

"Your account role has been updated to [New Role]. You now have access to [features]."

The system logs the role change with timestamp and admin identifier.

The user's interface updates to reflect new capabilities on next login.

Alternative Scenarios

A1. Insufficient Permissions

At Step 6, if the admin lacks authority to assign certain roles:

"You cannot assign [Role Name]. Only Super Administrators can grant this role."

A2. User Already Has Role

At Step 6, if attempting to assign current role:

"This user already has the [Role Name] role."

A3. Content Creator Requirements Not Met

At Step 8, if promoting to Content Creator but user hasn't met criteria:

"This user hasn't completed Content Creator training. Assign role anyway?"

Admin can proceed with override or require training first.

A4. Demoting Active Content Creator

At Step 8, if demoting a creator with published content:

"This user has [X] published courses. Demoting will affect content management. Reassign content?"

Admin must decide how to handle existing content.

6. Monitor Platform Analytics

Actor

Administrator

Main Success Scenario

The administrator logs into the admin dashboard.

The administrator navigates to "Platform Analytics."

The system displays a comprehensive analytics dashboard with widgets:

User Metrics: Total users, new registrations, active users (daily/weekly/monthly)

Engagement Metrics: Average session duration, lessons completed, exercises submitted

Content Metrics: Total courses, lessons, exercises; most popular content

Performance Metrics: System uptime, response times, error rates

Revenue Metrics: Enrollments, certification purchases, subscription status

Geographic Distribution: User locations, regional activity

The administrator can customize the date range (last 7 days, 30 days, 90 days, custom).

The administrator can filter by:

User segment (learners, content creators)

Course categories

Learning paths

Device types (desktop, mobile)

The administrator views detailed charts and graphs:

User growth trends (line graph)

Enrollment distribution (pie chart)

Peak usage times (heatmap)

Course completion rates (bar chart)

The administrator can drill down into specific metrics:

Clicks on "Course Completion Rate"

System shows breakdown by course, difficulty level, and time period

The administrator identifies trends:

Notice a drop in engagement on weekends

See spike in mobile usage

Identify popular learning paths

The administrator can export reports in multiple formats:

PDF (executive summary)

Excel (detailed data)

CSV (raw data)

The administrator schedules automated reports:

Weekly summary email

Monthly executive dashboard

Quarterly performance review

The system saves admin's preferred dashboard configuration.

Alternative Scenarios

A1. Insufficient Data

At Step 3, if platform is newly launched with minimal data:

"Limited data available. Analytics become more meaningful after 30+ days of activity."

A2. Data Loading Delays

At Step 3, if analytics take time to compile:

"Loading analytics... This may take a minute for large datasets."

A3. Export Limit Exceeded

At Step 9, if requesting very large data export:

"This export contains 100,000+ records. It will be processed in the background and emailed when ready."

A4. Real-Time Data Unavailable

At Step 3, if requesting real-time metrics during system maintenance:

"Real-time data temporarily unavailable. Showing last cached data from [timestamp]."

7. Review and Filter System Logs

Actor

Administrator

Main Success Scenario

The administrator navigates to "System Logs" in the admin panel.

The system displays log categories:

Security logs (authentication, failed logins, permission changes)

Error logs (application errors, API failures)

User activity logs (major actions, submissions)

Content logs (course creation, updates, deletions)

System performance logs (response times, resource usage)

The administrator selects "Security Logs."

The system displays recent security events with details:

Timestamp

Event type

User involved

IP address

Action taken

Outcome (success/failure)

The administrator can filter logs by:

Date/time range

Event severity (info, warning, error, critical)

User or IP address

Event type

The administrator searches for specific events (e.g., "failed login attempts from IP X").

The system highlights matching log entries.

The administrator can expand log entries for detailed information:

Full error stack trace

Request parameters

System state at time of event

The administrator can export filtered logs for analysis.

The system allows the administrator to flag logs for follow-up investigation.

The administrator can set up alerts for specific log patterns:

Multiple failed logins from same IP → possible attack

Spike in errors → system issue requiring attention

Alternative Scenarios

A1. Excessive Log Volume

At Step 4, if millions of log entries exist:

"Showing most recent 10,000 entries. Narrow your search or time range for specific logs."

A2. Sensitive Information in Logs

At Step 8, if logs contain sensitive data:

The system masks passwords, tokens, personal data

Only super admins can view unmasked logs with additional authentication

A3. Log Storage Full

At Step 2, if log storage approaching limit:

"Warning: Log storage at 85% capacity. Archive or delete old logs to prevent data loss."

8. Remove Inappropriate Content

Actor

Administrator

Main Success Scenario

The administrator receives a content flagging notification or browses flagged content.

The administrator navigates to "Content Moderation" section.

The system displays pending moderation queue:

Flagged courses

Flagged exercises

Flagged forum posts

Flagged solutions

Reported user profiles

Each item shows:

Content preview

Reporter information

Reason for flag

Timestamp

Content creator

The administrator selects a flagged item to review.

The system displays the full content with context.

The administrator evaluates against platform guidelines:

Offensive language

Plagiarized content

Inappropriate images

Misleading information

Spam or advertising

If content violates guidelines, the administrator chooses action:

Remove content immediately

Require revision by creator

Issue warning to creator

Suspend creator account

The administrator selects "Remove Content."

The system prompts for removal reason (required for transparency).

The administrator enters: "Contains plagiarized code from [source]. Violates copyright policy."

The system removes the content from public view.

The system notifies the content creator:

"Your content '[Title]' has been removed for: [Reason]. You may appeal this decision or create compliant content."

If repeat violation, the system automatically escalates to account suspension.

The system logs all moderation actions for audit trail.

The reporter receives notification that their flag was reviewed and action taken.

Alternative Scenarios

A1. Content Doesn't Violate Guidelines

At Step 8, if content is acceptable:

Administrator selects "Dismiss Flag"

Enters reason: "Content reviewed - no violation found. Appropriate educational material."

Reporter notified that content was reviewed but approved

Flag dismissed from queue

A2. Borderline Content

At Step 8, if content is questionable but not clearly violating:

Administrator selects "Request Revision"

Specifies improvements needed

Creator has 7 days to revise

If not revised, content is removed

A3. False/Malicious Reporting

At Step 7, if multiple flags from same user are consistently dismissed:

"User [X] has filed 5+ false reports. Possible abuse of flagging system."

Administrator can warn or restrict user's flagging ability

A4. Emergency Content Removal

At Step 1, for severe violations (illegal content, safety concerns):

Administrator uses "Emergency Remove" option

Content immediately removed without notification delay

Account automatically suspended pending investigation

Legal team notified if necessary

9. Issue User Warnings

Actor

Administrator

Main Success Scenario

The administrator identifies a policy violation (minor infraction).

The administrator navigates to the user's account.

The administrator clicks "Issue Warning."

The system displays warning form with fields:

Violation type (dropdown: spam, inappropriate language, plagiarism, etc.)

Severity (Minor, Moderate, Severe)

Description of violation

Evidence (attach screenshots, links)

Suggested corrective action

The administrator fills in the form:

Violation: "Inappropriate forum language"

Severity: Minor

Description: "Used profanity in discussion thread on [date]"

Action: "Please review community guidelines and maintain respectful communication"

The administrator selects "Send Warning."

The system records the warning on user's account.

The system sends notification to the user:

Email and in-platform notification

Clear explanation of violation

Link to relevant policy

Consequences of repeated violations

The warning appears on user's account record (visible to admins only).

The system tracks warning count:

1st warning: Notice only

2nd warning: 24-hour activity restriction

3rd warning: 7-day suspension

4th warning: Permanent ban

User can acknowledge warning or submit an appeal.

The system logs the warning issuance.

Alternative Scenarios

A1. User Appeals Warning

After Step 11, if user submits appeal:

Administrator reviews appeal and additional context

Can uphold, modify, or rescind warning

User notified of appeal decision with explanation

Decision is final unless escalated to senior admin

A2. Warning Escalation Required

At Step 5, if violation is more serious than initially assessed:

Administrator changes severity to "Severe"

"This user has [X] prior warnings. Escalated action may be warranted."

Administrator can proceed with suspension instead

A3. Pattern of Violations

At Step 3, if user has prior warnings:

"This user has [X] prior warnings. Escalated action may be warranted."

Suggests automatic penalties based on policy

A4. Warning Expiration

Warnings expire after 90 days of good behavior

System automatically archives expired warnings

User's slate cleaned if no violations in 90 days

Fully Dressed Format Use Cases

10. Design Learning Path

Primary Actor

Administrator

Administrator: Wants to design a coherent, strategic curriculum that aligns with platform goals.

Content Creators: Need clear assignments and guidance on what content to create.

Learners: Need a clear, logical progression that builds on previous knowledge.

Platform: Needs well-structured paths that improve learning outcomes and retention.

Preconditions

Administrator must be logged in with appropriate privileges.

Multiple courses and lessons should exist in the system (or be planned).

Administrator should have curriculum design knowledge.

Postconditions

A complete learning path structure is created.

Content creators are assigned to specific modules/tiers.

Path is organized into skill tiers with clear progression.

Path is ready for content creation phase.

Path can be published when all content is completed.

Main Success Scenario

The administrator navigates to "Learning Path Management" in the admin panel.

The administrator clicks "Create New Learning Path."

The system displays the path creation wizard with fields:

Path name (e.g., "Python Full-Stack Developer")

Path description and learning objectives

Target audience (beginners, intermediate, advanced)

Estimated total duration (e.g., 6 months, 200 hours)

Career outcomes or certifications earned

Prerequisites (if any)

The administrator enters the basic path information.

Step 1: Define Skill Tiers Structure

The system displays a visual canvas for organizing content

The administrator creates skill tiers (levels):

Tier 1: Foundation (variables, data types, basic syntax)

Tier 2: Core Concepts (loops, functions, data structures)

Tier 3: Intermediate (OOP, file handling, APIs)

Tier 4: Advanced (frameworks, databases, deployment)

Tier 5: Mastery (architecture, optimization, real projects)

For each tier, the administrator defines:

Tier name and description

Learning objectives

Expected number of courses/lessons

Estimated time to complete tier

Tier completion criteria

Step 2: Assign Content Requirements

For each tier, the administrator specifies required content types:

Number of video lessons needed

Number of coding exercises needed

Number of quizzes/assessments needed

Step 3: Set Prerequisites and Dependencies

The administrator defines relationships between tiers:

Tier 2 requires 100% completion of Tier 1

Tier 3 requires 80% mastery of Tier 2 skills

Optional branches for advanced learners

The system visualizes dependencies as a flowchart.

Step 4: Assign Content Creators to Tiers

For each tier/module, the administrator clicks "Assign Creator."

The system displays a list of available content creators with:

Expertise areas

Current workload

Previous content quality ratings

Availability status

The administrator selects one or multiple creators for each tier:

Primary creator (responsible for main content)

Contributing creators (assist with specific topics)

Reviewer (quality checks)

The system displays assignment summary showing which creators are assigned where.

Step 5: Create Content Creation Timeline

The administrator sets deadlines for each tier:

Tier 1 content: Due in 4 weeks

Tier 2 content: Due in 8 weeks

And so on...

The administrator can set milestones (e.g., "50% of Tier 1 lessons by week 2")

Step 6: Configure Assessment Checkpoints

The administrator adds evaluation points between tiers:

End-of-tier quizzes (specify passing score: 70%)

Portfolio projects (define requirements)

Skill validation exercises

The administrator defines checkpoint passing criteria.

Step 7: Set Adaptive Learning Rules (Optional)

The administrator configures adaptive progression rules:

If learner struggles with topic X → recommend supplementary exercises

If learner excels → offer accelerated track options

If learner abandons for 7+ days → send encouragement notification

Step 8: Define Milestones and Rewards

The administrator creates milestone achievements:

25% completion → "Python Beginner" badge + 500 XP

50% completion → "Python Intermediate" badge + 1000 XP

75% completion → "Python Advanced" badge + 1500 XP

100% completion → Certificate + "Python Master" badge + 3000 XP

Step 9: Configure Enrollment Options

The administrator sets:

Enrollment type: Free / Paid / Premium

Entry requirements: Diagnostic quiz score / Prior experience

Maximum concurrent enrollments (if limited)

Certification fee (if applicable)

The administrator writes a compelling path overview for learners:

What you'll learn (detailed breakdown)

Career opportunities (job roles, salary ranges)

Success stories from graduates (if available)

The administrator adds preview content (free introductory lessons).

The administrator reviews the complete path structure.

The administrator clicks "Validate Learning Path."

System Validation Process:

Checks for circular dependencies (A requires B, B requires A)

Verifies all tiers have assigned creators

Ensures prerequisite logic is sound

Validates that content requirements are reasonable

Estimates total time commitment is realistic

The system reports validation results.

If validation passes, the administrator sees: "✓ Learning path structure validated successfully."

The administrator sets the path status:

Draft (visible only to admin and assigned creators)

In Development (creators can start working)

Beta (open to limited testers once content is ready)

Published (publicly available after all content is completed)

The administrator selects "In Development" to activate content creation.

Step 10: Notify Assigned Content Creators

The system sends notifications to all assigned creators:

"You've been assigned to create content for '[Path Name]' - [Tier/Module Name]."

Notification includes:

Content requirements

Deadlines

Guidelines and templates

Contact info for coordination

Assigned creators receive task assignments in their dashboards.

The system creates a project management view showing:

Content creation progress for each tier

Creator task statuses

Upcoming deadlines

Bottlenecks or delays

The administrator can monitor progress and send reminders.

The system displays: "Learning path '[Path Name]' created successfully! Content creators have been notified."

Alternative Scenarios

A1. Circular Dependency Detected

At Step 23, if prerequisites create a loop:

"✗ Circular dependency detected: Tier A → Tier B → Tier C → Tier A"

Shows visual diagram of the problematic chain

Validation fails; administrator must restructure

Suggests which prerequisite to remove to break cycle

A2. No Content Creators Available

At Step 10-11, if no creators match the required expertise:

"⚠ No content creators with '[Skill]' expertise are currently available."

Administrator options:

Recruit new creators

Assign less experienced creator with mentor support

Delay tier creation until suitable creator is available

A3. Content Creator Declines Assignment

After Step 28, if a creator declines:

Creator provides reason (workload, expertise mismatch, timeline)

System notifies administrator

Administrator must reassign to another creator

Timeline may need adjustment

A4. Unrealistic Time Commitment

At Step 23, if total estimated time is excessive:

"⚠ This path requires ~500 hours. Average learner completion for similar paths is 6-12 months. Consider breaking into multiple paths or reducing content."

Shows completion rate data for paths of similar length

Administrator can proceed or revise

A5. Content Requirements Exceed Creator Capacity

At Step 13, if deadlines are too aggressive:

"⚠ Current assignments require 200 hours of content creation in 4 weeks. Assigned creators have capacity for 120 hours. Adjust timeline or add creators."

Administrator must revise timeline or add more creators

A6. Tier Without Learning Objectives

At Step 6, if a tier lacks clear objectives:

"⚠ Tier [X] has no defined learning objectives. Creators need clear goals."

Administrator must add objectives before proceeding

A7. Missing Assessment Checkpoints

At Step 14-15, if few or no checkpoints exist:

"⚠ This path lacks assessment checkpoints. Learners may progress without adequate skill validation."

Recommends adding checkpoints every 20-30 hours of content

Administrator can add checkpoints or acknowledge and proceed

A8. Duplicate or Overlapping Path

At Step 22, if a very similar path exists:

"⚠ A similar learning path exists: '[Path Name]'. Overlap: 60% of content. This may confuse learners or dilute enrollments."

Shows comparison of content overlap

Administrator options:

Differentiate the new path clearly

Merge with existing path

Archive old path if replacing it

Proceed with justification

A9. Creator Workload Imbalance

At Step 11-12, if one creator is overloaded:

"⚠ [Creator Name] is assigned to 3 tiers with deadlines in the same month. Consider redistributing workload."

Suggests alternative creators

Administrator can adjust assignments

A10. Budget Constraints for Paid Creators

At Step 11, if assigning paid creators:

"⚠ Current assignments will cost $[X], exceeding the $[Y] budget. Adjust assignments or increase budget."

Administrator must optimize assignments

Extensions

E1. Path Branching

Administrator can design choice points in the path:

After Core Python, learner chooses:

Branch A: Data Science specialization

Branch B: Web Development specialization

Branch C: Automation/DevOps specialization

Each branch has unique content, assigned to specialized creators

E2. Collaborative Path Design

Multiple administrators can co-design a path:

Each contributes expertise in specific areas

System tracks changes and responsibilities

Approval workflow for major structural changes

E3. Path Templates

Administrator can use templates for common path types:

"Beginner to Professional" template

"Specialization Track" template

"Certification Prep" template

Templates include suggested tier structures and checkpoints

E4. Content Reuse from Existing Paths

Administrator can import tiers/modules from other successful paths:

Select existing content to include

System links to original content (doesn't duplicate)

Credits original creators

Useful for building hybrid or cross-domain paths

E5. Dynamic Path Updates

After publication, administrator can update path without disrupting active learners:

Add new optional modules

Deprecate outdated content (remains accessible to enrolled learners)

Update prerequisites if needed

System notifies active learners of updates with opt-in

E6. Path Analytics Dashboard (Post-Publication)

After content is created and path is published, administrator accesses analytics:

Enrollment trends over time

Completion rates per tier

Common drop-off points

Average time per module

Learner satisfaction ratings

Employment outcomes (if tracked)

Creator performance metrics

Data informs path improvements

E7. Certification Integration

Administrator can configure official certification:

Final comprehensive exam specifications

Portfolio review criteria

Interview simulation requirements

Digital credential design

Verification method (blockchain, QR code)

E8. Corporate/Academic Partnerships

Paths designed for institutions:

Align with specific curriculum standards

Include institutional branding

Provide instructor dashboard for monitoring groups

Export transcripts and grades

Bulk enrollment management

Special Requirements

The visual path designer must support drag-and-drop for organizing tiers.
The system must prevent circular dependencies through real-time validation.
Administrator must be able to visualize the entire path structure at a glance.
All creator assignments must be logged with timestamps.
System must send automated reminders to creators as deadlines approach.
Content creation progress must be trackable in real-time.
Administrators must be able to export path structure as PDF for documentation.
The system must support versioning for path updates.
All prerequisite logic must be clearly documented and testable.
System must handle paths with 50+ courses without performance degradation.
Path analytics must aggregate data without exposing individual learner privacy.
Paths must support localization for international audiences.

Frequency of Use

Moderate frequency by administrators. Typically 1-2 new major paths per quarter. High usage during platform expansion or curriculum revisions. Ongoing monitoring and updates for existing paths.

Open Issues

Should administrators require approval from senior management for new paths? How do we handle creator disputes over assignments or deadlines? Should there be financial incentives for creators who meet quality/timeline goals? Can AI assist in recommending optimal path structures based on learning science? How do we measure ROI for paths (enrollments vs. development cost)? Should learning paths have expiration dates or version numbers?

5.3.2 Content Creator Use Cases

Brief Format Use Cases

1. View Created Content

The content creator views a list of all courses, lessons, and exercises they have authored.

2. Preview Lesson

The content creator previews how learners will see and interact with a lesson before publishing.

3. Duplicate Exercise

The content creator clones an existing exercise as a template for creating similar challenges.

4. Delete Draft

The content creator removes unpublished course materials or exercises from their drafts.

Casual Format Use Cases

5. Register Account

Actor

Content Creator

Main Success Scenario

The Content Creator navigates to the "Sign Up" page of the platform.

The Content Creator selects the "Content Creator" role from account type options.

The Content Creator provides required details:

Full name

Email address

Password (with confirmation)

Username

Resume/CV upload

The Content Creator agrees to Terms and Conditions and submits the form.

The system validates input (email format, password strength, username uniqueness, resume/CV format).

The system sends a verification email to the provided address.

The Content Creator clicks the OTP in the email.

Admin activates the account after reviewing the resume/CV.

The system redirects to the login page.

The Content Creator logs in successfully and sees a welcome message.

Alternative Scenarios

A1. Email Already Exists

At Step 5, if the email is already registered, the system displays:

"An account with this email already exists. Please log in or use a different email."

A2. Weak Password

At Step 5, if the password doesn't meet security criteria (minimum 8 characters with uppercase, lowercase, numbers, special characters), the system displays:

"Your password must be at least 8 characters long and include uppercase, lowercase, numbers, and symbols."

A3. Username Taken

At Step 5, if the username is already in use, the system displays:

"This username is already taken. Please choose a different one."

A4. Admin Reject Resume/CV

At Step 8, if the admin rejects the uploaded resume/CV after review, the system displays:

"Your resume/CV did not meet our criteria. Please update and resubmit."

6. Login to System

Actor

Content Creator

Main Success Scenario

The content creator navigates to the login page.

The content creator enters their email and password.

The content creator clicks "Login."

The system validates credentials.

The system authenticates the content creator and redirects to the dashboard.

The content creator sees their personalized dashboard with progress and recommendations.

Alternative Scenarios

A1. Incorrect Credentials

At Step 4, if credentials are invalid, the system displays:

"Incorrect email or password. Please try again."

A2. Account Not Verified

At Step 4, if the email is not verified, the system displays:

"Please verify your email address before logging in. Check your inbox for the OTP."

A3. Account Suspended

At Step 4, if the account is suspended, the system displays:

"Your account has been suspended. Please contact support for assistance."

7. Create Course

Actor

Content Creator

Main Success Scenario

The content creator logs into the platform.

The content creator navigates to "Content Management" section.

The content creator clicks "Create New Course."

The system displays a course creation form with fields:

Course title

Course description

Programming language (Python/JavaScript/Multi-language)

Difficulty level (Beginner/Intermediate/Advanced)

Estimated duration

Prerequisites

Course thumbnail image

The content creator fills in all required information.

The content creator organizes the course into modules:

Adds module titles

Orders modules sequentially

Assigns estimated time per module

The content creator clicks "Create Course."

The system validates all inputs and generates a unique course ID.

The system creates the course structure and saves it as a draft.

The system displays:

"Course created successfully! Now you can add lessons and exercises."

The content creator is redirected to the course dashboard to begin adding content.

Alternative Scenarios

A1. Missing Required Fields

At Step 7, if required fields are empty:

"Please complete all required fields: [Field Names]."

Incomplete fields are highlighted in red.

A2. Duplicate Course Title

At Step 8, if a course with the same title exists:

"A course with this title already exists. Please choose a different title or modify the existing course."

A3. Invalid Image Format

At Step 5, if the thumbnail isn't in an accepted format:

"Please upload an image in JPG, PNG, or WebP format."

A4. Course Creation Limit Reached

At Step 3, if the creator has reached their course limit:

"You've reached the maximum number of draft courses (5). Please publish or delete existing drafts."

8. Create Lesson

Actor

Content Creator

Main Success Scenario

The content creator selects an existing course from their dashboard.

The content creator selects a module within the course.

The content creator clicks "Add New Lesson."

The system displays the lesson creation interface with sections:

Lesson title

Lesson objectives

Content type selection (Text/Video)

Estimated completion time

The content creator enters the lesson title and objectives.

The content creator creates multi-format content:

Writes explanatory text with rich formatting

Uploads or embeds video tutorial

The content creator adds code snippets with syntax highlighting.

The content creator sets lesson order within the module.

The content creator can mark the lesson as:

Draft (not visible to learners)

Published (immediately available)

Scheduled (available on specific date)

The content creator clicks "Save Lesson."

The system validates content and saves the lesson.

The system displays:

"Lesson saved successfully!"

Alternative Scenarios

A1. Video Upload Fails

At Step 6, if video upload encounters an error:

"Video upload failed. Please ensure the file is under 500MB and in MP4 format."

Text content is saved as draft automatically.

A2. Content Too Short

At Step 11, if the lesson content is minimal:

"This lesson appears brief. Consider adding more detail to help learners understand the concept."

The creator can proceed or add more content.

9. Add Multimedia Content

Actor

Content Creator

Main Success Scenario

The content creator is editing a lesson.

The content creator clicks "Add Media" in the content editor.

The system displays media upload options:

Upload video file

Embed YouTube/Vimeo link

Upload images/diagrams

Add audio explanations

The content creator selects "Upload Video."

The content creator selects a video file from their device.

The system validates file size (max 500MB) and format (MP4, WebM).

The system displays upload progress bar.

The video uploads successfully to cloud storage.

The system generates a video player preview.

The content creator positions the video within the lesson content.

The content creator adds captions or transcripts (optional).

The content creator saves the lesson with embedded media.

The system confirms:

"Media added successfully!"

Alternative Scenarios

A1. File Size Exceeds Limit

At Step 6, if the video is larger than 500MB:

"Video file is too large. Please compress to under 500MB or use an external hosting link."

A2. Unsupported Format

At Step 6, if the file format isn't supported:

"This format is not supported. Please upload MP4 or WebM files."

A3. Upload Interrupted

At Step 7, if internet connection drops:

The system attempts to resume upload.

If unsuccessful after 3 attempts:

"Upload interrupted. Please try again."

A4. Embed Link Invalid

At Step 4, if an external video link doesn't work:

"Unable to embed this link. Please verify the URL and privacy settings."

10. Localize Content

Actor

Content Creator

Main Success Scenario

The content creator selects a published course or lesson.

The content creator clicks "Add Translation."

The system displays available languages (Arabic, English).

The content creator selects the target language (e.g., Arabic).

The system creates a duplicate content template with original text.

The content creator translates:

Lesson titles and descriptions

Content paragraphs

Code comments

Exercise instructions

The content creator adjusts formatting for RTL (right-to-left) if translating to Arabic.

The content creator can use AI-assisted translation for initial draft.

The content creator reviews and refines the AI-generated translation.

The content creator saves the localized version.

The system marks the content as available in multiple languages.

Learners can now switch between languages when viewing the content.

Alternative Scenarios

A1. AI Translation Unavailable

At Step 8, if AI service is down:

"AI translation is temporarily unavailable. Please translate manually."

A2. Incomplete Translation

At Step 10, if some sections remain untranslated:

"Some content is still in [Original Language]. Do you want to save anyway?"

The creator can save as draft or complete translation.

11. Categorize Exercise Difficulty

Actor

Content Creator

Main Success Scenario

The content creator is creating or editing an exercise.

The system displays difficulty level options:

Beginner (Basic syntax and concepts)

Intermediate (Multiple concepts, logic building)

Advanced (Complex algorithms, optimization)

Expert (Real-world problems, system design)

The content creator selects the appropriate difficulty.

The system displays difficulty criteria to guide selection.

The content creator assigns skill tags (e.g., "loops", "arrays", "recursion").

The system estimates average completion time based on difficulty.

The content creator can test the exercise themselves to verify difficulty.

The content creator saves the categorization.

The system uses this information for:

Adaptive learning path recommendations

Filtering in course catalog

XP reward calculation

Alternative Scenarios

A1. Difficulty Mismatch Detected

At Step 8, if the system's AI analysis suggests different difficulty:

"Our analysis suggests this exercise may be [Suggested Level]. Would you like to review?"

The creator can keep their choice or adjust.

12. Update Course Materials

Actor

Content Creator

Main Success Scenario

The content creator navigates to "My Courses."

The content creator selects a published course.

The content creator identifies content to update (lesson, exercise, video).

The content creator clicks "Edit."

The system loads the content in edit mode.

The content creator makes changes:

Updates outdated information

Fixes errors or typos

Improves explanations

Adds new examples

The content creator saves changes.

The system creates a new version and maintains version history.

If the course has active learners, the system displays:

"[X] students are enrolled. Notify them of updates?"

The content creator chooses to send update notification.

Enrolled learners receive:

"[Course Name] has been updated with new content!"

The system logs all changes for audit trail.

Alternative Scenarios

A1. Breaking Changes

At Step 6, if changes affect exercise solutions or grading:

"This change may affect existing student submissions. Consider creating a new exercise instead."

A2. Multiple Editors Conflict

At Step 5, if another creator is editing simultaneously:

"[Creator Name] is currently editing this content. Changes may conflict."

The system locks editing or enables collaborative editing mode.

13. Review Student Submissions

Actor

Content Creator

Main Success Scenario

The content creator navigates to "Course Management" dashboard.

The content creator selects a lesson in specific course to review submissions.

The system displays recent submissions for the creator's lesson.

The content creator filters by:

Execution metrics (time/memory)

Test case pass rate

Submission date

The content creator selects a student submission to review.

The system displays:

Student information (anonymous option available)

Problem statement

Student's code solution

Test case results

Execution metrics

The content creator reviews the code for:

Correctness

Code quality and style

Efficiency

Best practices

The content creator provides written feedback.

The content creator clicks "Submit Review."

The system saves the review and updates the student's grade.

The student receives notification with feedback.

Alternative Scenarios

A1. Auto-Graded Exercise

At Step 4, if the exercise is automatically graded:

"This exercise was automatically graded. Manual review is optional."

The creator can still provide additional feedback.

A2. Plagiarism Suspected

At Step 6, if the system detects potential plagiarism:

The system flags the submission with similarity score.

The creator investigates and can report if confirmed.

14. Manage Course Structure

Actor

Content Creator

Main Success Scenario

The content creator selects a course from their dashboard.

The content creator clicks "Edit Course Structure."

The system displays the course outline with all modules and lessons.

The content creator can:

Drag and drop to reorder modules

Drag and drop to reorder lessons within modules

Add new modules

Rename modules

Delete modules (with confirmation)

The content creator sets prerequisites:

Marks lessons that must be completed before others unlock

Creates skill dependencies

The content creator saves the new structure.

The system validates that prerequisites don't create circular dependencies.

The system updates the course structure.

If students are enrolled, the system adjusts their progress tracking.

The system displays:

"Course structure updated successfully!"

Alternative Scenarios

A1. Circular Dependency Detected

At Step 7, if prerequisites create a loop:

"Error: This creates a circular dependency. Lesson A cannot require Lesson B if Lesson B requires Lesson A."

Changes are not saved until resolved.

A2. Active Students Affected

At Step 6, if reordering affects students mid-course:

"[X] students are currently progressing through this course. Major restructuring may confuse them."

The creator can proceed with caution or schedule changes.

Fully Dressed Format Use Cases

15. Create Coding Exercise

Primary Actor

Content Creator

Content Creator: Wants to design effective, fair exercises that test specific skills.

Learners: Need clear instructions, fair test cases, and appropriate difficulty.

Platform: Needs quality-controlled exercises that can be auto-graded reliably.

Preconditions

Content creator must be logged in and authorized.

Content creator must have at least one course created.

Content creator must have completed platform training on exercise creation.

Postconditions

Exercise is created with complete problem statement, test cases, and model solution.

Exercise is saved as draft and ready for validation.

Exercise metadata is stored in the database.

Main Success Scenario

The content creator navigates to a course lesson.

The content creator clicks "Add Exercise."

The system displays the exercise creation wizard with tabs:

Problem Details

Test Cases

Model Solution

Hints

Metadata

Problem Details Tab: The content creator enters:

Exercise title (clear, concise)

Problem statement with context

Input format explanation

Output format explanation

Example inputs and outputs (2-3 examples)

Constraints (time limits, input ranges)

The content creator writes starter code template (optional).

Test Cases Tab: The content creator creates test cases:

At least 5 test cases (minimum requirement)

Mix of edge cases, typical cases, and boundary cases

For each test case: input data, expected output, visibility (public/hidden)

Test case descriptions explaining what is being tested

The content creator marks 2-3 test cases as public (visible to learners).

The content creator marks remaining cases as hidden (for final validation).

Model Solution Tab: The content creator writes a reference solution:

Correct, efficient code in the target language

Well-commented for educational value

Multiple approaches (optimal, brute-force, alternative methods)

The content creator runs the model solution against all test cases.

The system validates that the model solution passes all test cases.

Hints Tab: The content creator creates progressive hints:

Level 1: Conceptual hint (approach suggestion)

Level 2: Algorithmic hint (specific strategy)

Level 3: Implementation hint (code structure)

Metadata Tab: The content creator sets:

Difficulty level (Beginner/Intermediate/Advanced)

Estimated time to complete

Skill tags (e.g., "arrays", "sorting", "dynamic-programming")

XP reward value

The content creator clicks "Save as Draft."

The system saves the exercise in draft status.

The system displays:

"Exercise saved successfully! Proceed to validation when ready."

The content creator can:

Continue editing

Submit for validation (goes to Use Case 16)

Delete draft

The content creator clicks "Submit for Validation."

The system transitions to Use Case 16 (Validate Exercise Before Publishing).

Alternative Scenarios

A1. Insufficient Test Cases

At Step 14, if fewer than 5 test cases exist:

"Add at least 5 test cases before saving."

Save is blocked until minimum requirement is met.

A2. Model Solution Fails Test Cases

At Step 11, if the model solution doesn't pass all tests:

"Your model solution failed test case [X]. Expected: [Y], Got: [Z]."

The creator must fix either the solution or the test case before saving.

A3. Missing Required Fields

At Step 14, if mandatory fields are empty:

"Complete all required fields: [List]"

Incomplete sections are highlighted in red.

A4. Auto-Save During Creation

Throughout the process, the system auto-saves progress every 2 minutes.

If creator closes browser, they can resume from last saved state.

A5. Multiple Programming Languages

At Step 9, if the exercise supports multiple languages:

Creator must provide model solutions in each language.

Each solution is validated independently before saving.

Language-specific hints may be needed.

Extensions

E1. Complexity Analysis Addition

Creator adds Big O notation explanations:

Time complexity of optimal solution

Space complexity analysis

Comparison with alternative approaches

This enhances educational value.

E2. Interactive Test Case Builder

System provides GUI to build test cases:

Generate random inputs within constraints

Automatically compute expected outputs using model solution

Visualize test coverage

E3. Import from External Sources

Creator can import exercise templates from:

Other platforms (with proper attribution)

Previous exercises (as starting point)

Community-contributed templates

Special Requirements

All data must be auto-saved every 2 minutes to prevent loss.
Draft exercises are only visible to the creator.
Model solutions must be encrypted in database.
System must support Python, JavaScript, and eventually Java/C++.
Problem statements must pass basic grammar check before saving.
Exercise creation interface must be accessible via keyboard navigation.

Frequency of Use

High frequency during initial course development. Moderate ongoing use as creators add content. Estimated 10-20 exercises created per active content creator per month.

Open Issues

Should we allow saving incomplete exercises with warnings?

How long should drafts be retained before auto-deletion?

Should creators earn points for creating quality exercises?

16. Validate Exercise Before Publishing

Primary Actor

Content Creator

Content Creator: Wants assurance that the exercise functions correctly before peer review.

Learners: Need exercises that work properly without technical issues or unfair test cases.

Platform Quality Team: Wants to maintain high content standards.

Peer Reviewers: Need well-validated exercises to review efficiently.

Preconditions

Exercise must be created and saved as draft (Use Case 15 completed).

Content creator must be logged in.

Validation API and code execution environment must be operational.

Exercise must have minimum required components (problem, test cases, solution).

Postconditions

Exercise is thoroughly tested and validated.

Validation report is generated and stored.

If validation passes, exercise is ready for peer review assignment.

If validation fails, creator receives detailed feedback for improvements.

Main Success Scenario

The content creator has completed exercise creation (from Use Case 15).

The content creator clicks "Submit for Validation."

The system displays:

"Beginning comprehensive validation... This may take 30-60 seconds."

Step 1: Model Solution Validation

System executes model solution against all test cases

Measures execution time and memory usage

Checks for runtime errors or infinite loops

Validates against time and memory constraints

The system confirms:

"✓ Model solution passes all [X] test cases."

Step 2: Test Case Quality Check

System analyzes test case diversity

Checks for edge cases: empty inputs, maximum values, negative numbers, boundary conditions

Verifies hidden tests differ meaningfully from public tests

Ensures test cases cover multiple solution approaches

Validates test case descriptions are clear

The system reports:

"✓ Test cases provide adequate coverage."

Step 3: Problem Statement Analysis

AI reviews problem statement for clarity and completeness

Checks grammar and spelling

Identifies ambiguous phrasing

Verifies examples match expected input/output format

Ensures constraints are clearly defined

The system reports:

"✓ Problem statement is clear and complete."

Step 4: Difficulty Calibration

System estimates difficulty based on:

Solution complexity (cyclomatic complexity, lines of code)

Required concepts (data structures, algorithms)

Test case difficulty

Compares with creator's assigned difficulty

The system reports:

"✓ Estimated difficulty matches assigned level (Intermediate)."

Step 5: Hint Quality Assessment

Validates that hints don't reveal complete solution

Checks hint progression (conceptual → specific → implementation)

Ensures hints are appropriate for difficulty level

The system reports:

"✓ Hints provide appropriate guidance without spoiling solution."

Step 6: Security and Fairness Check

Ensures no hardcoded test cases in problem description

Validates that public test cases don't make hidden cases obvious

Checks for potential exploitation methods

The system reports:

"✓ Exercise meets security and fairness standards."

The system compiles a comprehensive validation report showing all checks.

The system displays final status:

"✓ Validation Complete: PASSED"

The content creator reviews the full validation report.

The system offers options:

Assign for Peer Review (proceed to step 20)

Make Revisions (return to editing)

Save for Later (keep in validated draft status)

The content creator clicks "Assign for Peer Review."

The system displays peer reviewer selection interface.

The system recommends 1-3 qualified reviewers based on:

Expertise in relevant programming language

Experience with similar difficulty levels

Current review workload

Reviewer ratings and reliability

The content creator selects reviewers (1-3 reviewers).

The system sends notifications to selected reviewers:

"You've been assigned to review exercise '[Title]'. Please complete within 3-5 business days."

The exercise is added to each reviewer's review queue.

The system sets review deadline (5 business days from assignment).

The system displays to creator:

"Exercise assigned for peer review. You'll be notified when reviews are complete."

The exercise status changes to "Under Peer Review."

The creator receives a confirmation summary:

Validation results

Assigned reviewers

Expected review completion date

The system transitions to peer review workflow (not detailed in this use case).

Alternative Scenarios

A1. Model Solution Fails Test Cases

At Step 4-5, if model solution fails any test:

"✗ Model solution failed test case #[X]"

Shows: Input provided, Expected output, Actual output, Error message

Validation status: FAILED

Creator options:

Fix model solution

Modify test case

Add explanation if intentional

Cannot proceed to peer review until resolved

A2. Missing Edge Cases

At Step 6-7, if edge case coverage is insufficient:

"⚠ Test cases may not cover edge scenarios: [empty input, single element, maximum constraints]"

Validation status: PASSED WITH WARNINGS

Creator can:

Add recommended edge cases

Proceed to peer review with warning documented

Peer reviewers will see this warning

A3. Problem Statement Unclear

At Step 8-9, if AI detects ambiguity:

"⚠ Problem statement may be unclear: '[specific phrase]' could be interpreted multiple ways."

Provides revision suggestions with examples

Validation status: PASSED WITH WARNINGS

Creator should clarify but can proceed

Peer reviewers will be asked to verify clarity

A4. Difficulty Mismatch

At Step 10-11, if estimated difficulty differs significantly:

"⚠ This exercise appears to be [Advanced] but is marked [Intermediate]. Consider adjusting."

Shows difficulty scoring breakdown

Validation status: PASSED WITH WARNINGS

Creator can:

Adjust difficulty level

Provide justification for current level

Proceed with warning (reviewers will validate)

A5. Execution Timeout

At Step 4, if model solution exceeds time limit:

"✗ Model solution exceeded [N]-second time limit. Execution time: [X]s"

Validation status: FAILED

Creator must:

Optimize solution

Adjust time constraints

Reconsider problem complexity

Cannot proceed until resolved

A6. Test Cases Too Similar

At Step 6, if hidden tests are predictable:

"⚠ Hidden test cases appear similar to public tests. Add more diverse scenarios."

Suggests specific missing scenarios

Validation status: PASSED WITH WARNINGS

Creator should improve diversity

Reviewers will test with their own approaches

A7. No Available Reviewers

At Step 22-23, if no suitable reviewers available:

"No reviewers currently available with matching expertise. Options:"

Wait for reviewers to become available (estimated: X days)

Expand reviewer criteria

Request admin to assign reviewers

Exercise remains in validated draft status

A8. Creator Cancels Review Assignment

At Step 23, if creator changes mind:

Creator clicks "Cancel Assignment"

Exercise returns to validated draft status

Can be edited or assigned later

A9. Grammatical Errors

At Step 8-9, if grammar issues detected:

System highlights errors with suggestions

Auto-correct offered for minor issues

Validation status: PASSED WITH WARNINGS

Creator should review and fix

Reviewers will verify corrections

A10. Validation Service Unavailable

At Step 3, if validation API fails:

"Validation service temporarily unavailable. Options:"

Retry now

Save and retry later

Contact support if issue persists

Exercise saved but not validated

Creator notified when service resumes

A11. Multiple Languages, Different Results

At Step 4-5, if exercise supports Python and JavaScript:

If Python solution passes but JavaScript fails:

System reports issues separately by language

Validation status: PARTIALLY FAILED

Creator must fix failing language implementation

All language versions must pass before proceeding

A12. Hints Reveal Too Much

At Step 12-13, if hints are too specific:

"⚠ Hint level [X] may reveal too much of the solution. Consider making it more conceptual."

Validation status: PASSED WITH WARNINGS

Shows which hints are problematic

Reviewers will test hint effectiveness

Extensions

E1. Automated Test Generation Suggestions

After validation, system offers to generate additional test cases:

Creates random inputs within constraints

Uses model solution to compute expected outputs

Creator reviews and approves generated tests

Re-validates with new tests

E2. Validation Report Export

Creator can download detailed validation report as PDF

Includes:

All validation checks and scores

Recommendations for improvement

Comparison with similar exercises

Quality metrics

Useful for documentation or training

E3. Incremental Validation

For large exercises with many test cases:

System validates in stages, showing progress

Creator can cancel if early stages reveal issues

Partial results saved for faster re-validation

E4. A/B Testing Suggestion

If exercise is similar to existing ones:

System suggests A/B testing with learners

Tracks which version performs better

Informs future exercise design

E5. Reviewer Self-Selection

Instead of creator assigning reviewers:

Creator can post exercise to "Review Marketplace"

Qualified reviewers volunteer to review

Creator selects from volunteers

Faster assignment in active communities

Special Requirements

Validation must complete within 60 seconds for standard exercises.
All validation checks must be logged for quality assurance auditing.
Validation must detect common anti-patterns (hardcoded solutions, trivial test cases).
System should cache validation results; re-validation only needed if exercise changes.
Validation API must handle concurrent requests from multiple creators.
Failed validations must provide actionable guidance, not just error messages.
Warnings must be clearly documented for peer reviewers.
Reviewer recommendations must consider expertise, workload, and reliability.
System must prevent assigning reviewers who have conflicts of interest.

Frequency of Use

Every exercise must be validated before peer review (100% usage). Re-validation after any exercise modification. Estimated 50-100 validations per active content creator over platform lifetime.

Open Issues

Should we implement tiered validation (basic, standard, rigorous) based on difficulty?

How do we handle edge cases where automated validation gives false positives?

Should validation scores affect creator reputation?

Can we use machine learning to improve validation accuracy over time?

Should we allow creators to skip certain validation checks with justification?

How do we balance validation thoroughness with creator experience?

17. Contribute to Learning Path

Primary Actor

Content Creator

Content Creator: Wants clear requirements and reasonable deadlines for content creation.

Administrator: Needs quality content delivered on time to complete the learning path.

Learners: Will benefit from well-crafted, cohesive content within the path.

Preconditions

Content creator must be logged in and authorized.

Administrator must have created a learning path and assigned the creator to a specific tier/module.

Content creator must have received assignment notification.

Postconditions

Required content (lessons, exercises) is created within the assigned tier.

Content meets quality standards and aligns with path objectives.

Administrator can review and approve the content.

Tier is marked as complete and ready for integration.

Main Success Scenario

The content creator receives a notification:

"You've been assigned to create content for '[Path Name]' - [Tier/Module Name]."

The content creator navigates to "My Assignments" in their dashboard.

The system displays the learning path assignment with details:

Path name and overall objectives

Assigned tier/module name

Content requirements:

Number of lessons to create (e.g., 5 video lessons)

Number of exercises to create (e.g., 10 coding challenges)

Learning objectives for this tier

Target audience and skill level

Deadline for completion

Guidelines and templates provided by administrator

Contact information for coordination

The content creator reviews the requirements and clicks "Accept Assignment."

The system creates a task board for the creator showing:

Checklist of required content items

Progress tracker (0% complete)

Deadline countdown

Step 1: Plan Content Structure

The creator outlines topics to cover in each lesson

Maps exercises to specific learning objectives

Designs project requirements

The creator can request clarification from the administrator if objectives are unclear.

Step 2: Create Lessons

The creator follows Use Case 8 (Create Lesson) for each required lesson

Ensures lessons align with tier objectives

Covers prerequisite knowledge appropriately

Follows platform style guidelines

The system tracks completed lessons and updates progress (e.g., 30% complete).

Step 3: Create Exercises

The creator follows Use Case 15-16 (Create and Validate Coding Exercise) for each exercise

Ensures difficulty aligns with tier level

Ties exercises to specific lesson concepts

Creates diverse problem types

The system tracks completed exercises and updates progress (e.g., 60% complete).

Step 5: Review Content Cohesion

The creator reviews all created content for the tier

Ensures logical flow between lessons

Verifies exercises progressively build skills

Checks that project appropriately challenges learners

The creator can preview the entire tier as a learner would experience it.

Step 6: Internal Quality Check

The creator runs through their own content:

Tests all code examples

Verifies exercise solutions

Checks for typos or errors

Ensures multimedia loads correctly

The creator makes any necessary revisions.

Step 7: Mark as Ready for Review

The creator clicks "Submit for Administrator Review."

The system prompts:

"Are you sure all content is complete and meets quality standards?"

The creator confirms submission.

The system notifies the administrator:

"[Creator Name] has submitted content for '[Tier Name]' in '[Path Name]'. Ready for review."

The system changes the tier status to "Under Administrator Review."

The creator's task board shows "Awaiting Review" status.

Administrator Review Phase:

Administrator reviews all content (separate use case)

Administrator can approve, request revisions, or reject

If approved:

Creator receives notification:

"Your content for '[Tier Name]' has been approved! Great work."

Creator earns XP/badges for completing assignment

Content is integrated into the learning path

If revisions requested:

Creator receives detailed feedback with specific issues

Creator makes requested changes

Creator resubmits (returns to Step 17)

The system tracks the creator's contribution for analytics and reputation.

Alternative Scenarios

A1. Creator Declines Assignment

At Step 4, if the creator cannot accept:

Creator clicks "Decline Assignment"

System prompts for reason (workload, expertise mismatch, timeline)

System notifies administrator to reassign

Creator is removed from assignment

A2. Deadline Extension Needed

Before deadline, if creator needs more time:

Creator clicks "Request Extension"

Provides justification and proposed new deadline

Administrator reviews and approves/denies

If approved, deadline is updated

If denied, creator must meet original deadline or decline

A3. Clarification Required

At Step 7, if objectives are unclear:

Creator clicks "Request Clarification"

Sends specific questions to administrator

Administrator responds with guidance

Creator proceeds with clarified understanding

A4. Content Requirements Change

During content creation, if administrator updates requirements:

Creator receives notification of changes

System highlights what changed

Creator acknowledges changes

Deadline may be adjusted if significant changes

A5. Missed Deadline

If creator doesn't submit by deadline:

System sends urgent reminder 3 days before deadline

If still missed:

Administrator is notified

Administrator can extend deadline or reassign

Creator's reputation may be affected

A6. Revisions Requested Multiple Times

At Step 24, if content is rejected twice:

Administrator and creator have a coordination meeting

Discuss issues and expectations

If third submission also fails:

Assignment may be reassigned

Creator's compensation/reputation affected

A7. Technical Issues During Creation

If system errors prevent content creation:

Creator reports issue to support

System logs the issue

Deadline may be extended if issue is system-wide

Creator can save drafts to prevent data loss

A8. Collaborating with Other Creators

If multiple creators are assigned to the same tier:

System provides shared workspace

Creators can see each other's progress

Chat/comment feature for coordination

One creator designated as "lead" to avoid conflicts

Extensions

E1. Early Completion Bonus

If creator completes high-quality content ahead of schedule:

Creator earns "Early Bird" badge

May receive bonus XP or recognition

Reputation score increases

E2. Feedback and Iteration

After path is published and learners use the content:

Creator receives analytics on their tier:

Completion rates

Average time spent

Learner satisfaction ratings

Common misconceptions

Creator can update content based on feedback

E3. Content Reuse Permission

Creator can request to reuse tier content in personal courses:

Submits request to administrator

If approved, content can be adapted for other uses

Original path retains rights to the content

E4. Compensation Tracking

For paid creators:

System tracks time spent on assignment

Milestones trigger partial payments

Final approval triggers full payment

Invoicing generated automatically

Special Requirements

The task board must clearly show progress and remaining work.
Creators must be able to save work-in-progress at any time (auto-save every 2 minutes).
System must support version history for all created content.
Communication between creator and administrator must be logged.
Deadline reminders must be sent at 7 days, 3 days, and 1 day before due date.
Content submission must include a checklist confirmation (all requirements met).
Administrator feedback must be clear, actionable, and specific.

Frequency of Use

Moderate to high frequency depending on path creation activity. Each creator may have 2-5 active assignments at any time. Typically takes 2-6 weeks per tier assignment depending on complexity.

Open Issues

Should creators be able to collaborate in real-time on the same content?

How do we handle disputes between creator and administrator on content direction?

Should there be peer review before administrator review?

Can AI assist in identifying content gaps or quality issues?

5.3.3 Learner Use Cases

Brief Format Use Cases

1. View Profile

The learner views their profile information including avatar, bio, learning goals, and XP progress.

2. Change Theme

The learner switches between dark and light mode in the editor settings (or using switch sun/moon icon).

3. View Badges

The learner views their earned badges and achievements in their profile gallery.

4. Check Streak

The learner checks their current daily learning streak and streak milestones.

5. View Leaderboard

The learner views global, weekly, or friend-based leaderboards showing XP rankings.

6. Update Avatar

The learner uploads or changes their profile picture.

Casual Format Use Cases

7. Register Account

Actor

Learner

Main Success Scenario

The learner navigates to the "Sign Up" page of the platform or app.

The learner selects the "Learner" role from account type options.

The learner provides required details:

Full name

Email address

Password (with confirmation)

Username

The learner can register using social media accounts (Google, Github, LinkedIn) as an alternative.

The learner agrees to Terms and Conditions and submits the form.

The system validates input (email format, password strength, username uniqueness).

The system sends a verification email to the provided address.

The learner clicks the OTP in the email.

The system activates the account and redirects to the login page.

The learner logs in successfully and sees a welcome message.

Alternative Scenarios

A1. Email Already Exists

At Step 5, if the email is already registered, the system displays:

"An account with this email already exists. Please log in or use a different email."

A2. Weak Password

At Step 5, if the password doesn't meet security criteria (minimum 8 characters with uppercase, lowercase, numbers, special characters), the system displays:

"Your password must be at least 8 characters long and include uppercase, lowercase, numbers, and symbols."

A3. Username Taken

At Step 5, if the username is already in use, the system displays:

"This username is already taken. Please choose a different one."

8. Login to System

Actor

Learner

Main Success Scenario

The learner navigates to the login page in the platform or app.

The learner enters their email and password.

The learner can choose to log in using social media accounts (Google, Github, LinkedIn) as an alternative.

The learner clicks "Login."

The system validates credentials.

The system authenticates the learner and redirects to the dashboard.

The learner sees their personalized dashboard with progress and recommendations.

Alternative Scenarios

A1. Incorrect Credentials

At Step 4, if credentials are invalid, the system displays:

"Incorrect email or password. Please try again."

A2. Account Not Verified

At Step 4, if the email is not verified, the system displays:

"Please verify your email address before logging in. Check your inbox for the OTP."

A3. Account Suspended

At Step 4, if the account is suspended, the system displays:

"Your account has been suspended. Please contact support for assistance."

9. Recover Password

Actor

Learner

Main Success Scenario

The learner clicks "Forgot Password" on the login page.

The learner enters their registered email address.

The system validates the email.

The system sends a password OTP to the email.

The learner enters the OTP received.

The learner enters and confirms a new password.

The system updates the password.

The learner sees confirmation:

"Password reset successfully. You can now log in."

Alternative Scenarios

A1. Email Not Found

At Step 3, if the email isn't registered, the system displays:

"No account found with this email address."

A2. Link Expired

At Step 5, if the OTP expired, the system displays:

"This link has expired. Please request a new password reset."

10. Choose Learning Path

Actor

Learner

Main Success Scenario

The learner logs into the platform or app.

The learner navigates to the "Learning Paths" section.

The system displays available tracks (Fundamentals, Machine Learning, Cybersecurity, Full-Stack Development).

The learner selects their preferred learning path.

The system shows a detailed overview including modules, estimated time, and prerequisites.

The learner confirms their selection by clicking "Start Path."

The system updates the learner's dashboard with the selected path.

The learner receives a confirmation message:

"You've successfully enrolled in the [Path Name] learning path! Let's start coding."

Alternative Scenarios

A1. Prerequisite Not Met

At Step 6, if the learner lacks prerequisite skills, the system displays:

"This path requires basic programming knowledge. We recommend starting with [Beginner Path]."

The system offers to take a diagnostic quiz to determine the appropriate starting point.

A2. Already Enrolled in Path

At Step 6, if the learner is already enrolled, the system displays:

"You're already enrolled in this path. Continue learning from your dashboard."

11. View Lesson Content

Actor

Learner

Main Success Scenario

The learner navigates to their enrolled course from the dashboard.

The learner selects a module and clicks on a specific lesson.

The system displays the lesson content including:

Text explanation

Video tutorial

The learner reads/watches the content at their own pace.

The learner can pause, rewind, or fast-forward video content.

The system tracks time spent on the lesson.

The lesson is marked as complete when finished.

The system updates progress and unlocks the next lesson.

Alternative Scenarios

A1. Lesson Locked

At Step 2, if prerequisites aren't completed, the system displays:

"Complete the previous lessons to unlock this content."

A2. Content Loading Error

At Step 3, if content fails to load, the system displays:

"We're having trouble loading this lesson. Please refresh or try again later."

12. Complete Exercise

Actor

Learner

Main Success Scenario

The learner navigates to the exercises section of a lesson.

The learner selects an available coding challenge.

The system displays the problem statement, input/output examples, and starter code.

The learner writes code in the Code Editor in platform.

The learner drag/drop blocks of code in the blockly Editor in app.

The learner clicks "Run Tests" to validate their solution.

The system executes the code against test cases.

The system displays results showing passed/failed test cases.

If all tests pass, the learner clicks "Submit Solution."

The system awards XP and updates skill mastery.

The learner receives a success message with earned points.

Alternative Scenarios

A1. Tests Failed

At Step 7, if some tests fail, the system displays:

"Some test cases failed. Review the expected vs. actual output and try again."

The learner can request hints or revise their code.

A2. Syntax Error

At Step 6, if the code has syntax errors, the system displays:

"Syntax Error: [Error Description]. Check line [X]."

A3. Runtime Error

At Step 6, if the code causes a runtime error, the system displays:

"Runtime Error: [Error Description]. Your code crashed during execution."

13. Track Progress and View Learning Analytics

Actor

Learner

Main Success Scenario

The learner navigates to the "Progress & Analytics" section from the dashboard.

The system displays a comprehensive dashboard with two main views:

**Progress Overview**

**Detailed Analytics**

**Progress Overview Section** displays:

Completed modules and lessons

Current XP and level

Skill mastery percentages

Time spent learning

Streak information

**Detailed Analytics Section** displays:

Accuracy rates per skill

Time-to-completion trends

Learning velocity

Performance metrics with charts and graphs

The system highlights weak areas and recommends improvement exercises based on analytics.

The learner can view predictions and insights:

Estimated time to complete current path

Suggested focus areas

The system provides actionable recommendations based on combined progress and analytics data.

Alternative Scenarios

A1. No Progress Data

At Step 2, if the learner hasn't completed any content:

The system displays:

"Start your learning journey! Complete lessons to see your progress and analytics here."

Shows sample analytics dashboard with demo data

A2. Insufficient Data for Detailed Analytics

At Step 4, if there's not enough activity for meaningful analytics:

The system displays:

"Complete more lessons (at least 10) to unlock detailed analytics and insights."

Shows basic progress metrics only

Detailed analytics sections are grayed out with unlock requirements

A3. Data Loading Delays

At Step 2, if analytics take time to compile:

The system displays progress indicator:

"Loading your analytics... This may take a moment."

Shows cached data with timestamp while fresh data loads

14. Earn XP and Level Up

Actor

Learner

Main Success Scenario

The learner completes a lesson, exercise, or challenge.

The system calculates earned XP based on:

Task difficulty

Completion time

Accuracy

Streak bonuses

The system adds XP to the learner's total.

If the learner reaches a level threshold, the system triggers level-up animation.

The learner sees a congratulatory message with new level badge.

The system unlocks new content or features appropriate to the new level.

Alternative Scenarios

A1. Bonus XP Earned

At Step 2, if the learner completes on the first attempt or maintains a streak, the system displays:

"Bonus XP! You earned +[X] extra points for [reason]."

15. Set Language Preferences

Actor

Learner

Main Success Scenario

The learner navigates to Settings.

The learner selects "Language Preferences."

The system displays options for:

Interface language (Arabic/English)

Primary programming language (Python/JavaScript) in platform.

The learner makes selections and clicks "Save."

The system updates preferences and refreshes the interface.

The learner sees confirmation:

"Preferences updated successfully."

Alternative Scenarios

A1. Save Error

At Step 5, if saving fails, the system displays:

"Unable to save preferences. Please try again."

16. Bookmark Lesson

Actor

Learner

Main Success Scenario

The learner is viewing a lesson.

The learner clicks the "Bookmark" icon.

The system adds the lesson to the learner's bookmarks.

The learner sees confirmation:

"Lesson bookmarked!"

The learner can access bookmarks from their profile.

Alternative Scenarios

A1. Already Bookmarked

At Step 3, if the lesson is already bookmarked, the system removes it and displays:

"Bookmark removed."

17. Share Solution

Actor

Learner

Main Success Scenario

The learner completes an exercise successfully.

The learner navigates to the "Solution Gallery" section.

The learner clicks "Share My Solution."

The learner adds optional comments or explanations.

The learner submits the solution for community viewing.

The system publishes the solution with the learner's profile.

Other learners can view, upvote, and comment.

Alternative Scenarios

A1. Solution Not Approved

At Step 6, if the solution violates guidelines, moderators reject it with feedback.

Fully Dressed Format Use Cases

18. Enable Two-Factor Authentication

Primary Actor

Learner

Learner: Wants enhanced account security to protect personal data and progress.

Platform: Needs to reduce account compromise and unauthorized access.

Security Team: Wants to enforce best practices for account protection.

Preconditions

Learner must be logged in.

Learner must have a verified email address.

Learner must have access to a mobile device or authenticator app.

Postconditions

2FA is enabled on the learner's account.

Future logins require both password and verification code.

Backup codes are generated and stored securely.

Main Success Scenario

The learner navigates to Account Settings.

The learner selects "Security" tab.

The learner clicks "Enable Two-Factor Authentication."

The system displays 2FA setup options:

Authenticator app (recommended)

Email verification code

The learner selects "Authenticator App."

The system generates a QR code and secret key.

The system displays instructions:

"Scan this QR code with your authenticator app (Google Authenticator, Authy, etc.)"

The learner opens their authenticator app and scans the QR code.

The authenticator app adds the DuoCodo account and begins generating codes.

The system prompts: "Enter the 6-digit code from your authenticator app to confirm setup."

The learner enters the current code from their app.

The system validates the code.

The system generates 10 backup recovery codes.

The system displays the recovery codes with instructions:

"Save these codes securely. Each can be used once if you lose access to your authenticator."

The learner downloads or copies the recovery codes.

The learner confirms they've saved the codes by checking a box.

The system enables 2FA on the account.

The learner sees confirmation:

"Two-Factor Authentication is now active. Your account is more secure!"

The system logs out all other sessions for security.

Future logins now require:

Email/username + password

6-digit code from authenticator app

Alternative Scenarios

A1. Invalid Verification Code

At Step 12, if the code is incorrect:

"Invalid code. Please ensure you're entering the current 6-digit code from your authenticator app."

The learner can try again (up to 5 attempts).

After 5 failed attempts, setup is cancelled and must restart.

A2. Backup Codes Not Saved

At Step 16, if the learner tries to continue without confirming:

"Please confirm you've saved your backup codes. You won't be able to view them again."

The "Continue" button remains disabled until confirmed.

A3. Learner Chooses Email Method

At Step 5, if the learner selects email verification:

The system uses the registered email address.

The system sends a test verification code via email.

The learner enters the code to confirm.

Setup completes with email as the 2FA method.

A4. QR Code Won't Scan

At Step 8, if the learner can't scan the QR code:

The learner clicks "Can't scan? Enter code manually."

The system displays the secret key as text.

The learner manually enters the key into their authenticator app.

Setup continues from Step 10.

A5. Lost Authenticator Device

After 2FA is enabled, if the learner loses access:

During login, the learner clicks "Use backup code instead."

The learner enters one of their saved recovery codes.

The system validates the code and grants access.

The system prompts the learner to reconfigure 2FA.

The used recovery code is marked as consumed.

A6. All Backup Codes Used

If all 10 backup codes are exhausted:

The learner must contact support with identity verification.

Support verifies identity through:

Email verification

Security questions

Recent activity verification

Support can temporarily disable 2FA or reset it.

A7. Technical Error During Setup

At any step, if a system error occurs:

"We encountered an error during 2FA setup. Please try again or contact support."

The setup is rolled back; 2FA is not enabled.

The learner can retry after a few minutes.

Extensions

E1. Disable 2FA

The learner navigates to Security settings.

The learner clicks "Disable Two-Factor Authentication."

The system requires current password + 2FA code for confirmation.

The system warns about reduced security.

If confirmed, 2FA is disabled and all backup codes are invalidated.

E2. Regenerate Backup Codes

If the learner loses their backup codes:

The learner navigates to Security settings.

The learner authenticates with password + 2FA code.

The learner clicks "Generate New Backup Codes."

The system creates 10 new codes and invalidates old ones.

The learner saves the new codes securely.

E3. Change 2FA Method

The learner can switch from SMS to authenticator app (or vice versa):

The learner navigates to Security settings.

The learner selects "Change 2FA Method."

The system requires current 2FA verification.

Setup for new method proceeds as in main scenario.

E4. Trusted Devices

After successful 2FA login:

The system offers: "Trust this device for 30 days?"

If accepted, 2FA is not required on this device for 30 days.

Trusted devices can be managed in Security settings.

Special Requirements

2FA codes must expire after 30 seconds (standard TOTP protocol).
Backup codes must be cryptographically secure random strings.
The system must support time-based one-time passwords (TOTP) standard.
SMS delivery must occur within 60 seconds.
Recovery codes must be hashed in the database, not stored in plain text.
The system must rate-limit 2FA verification attempts (max 5 per 15 minutes).
All 2FA setup and verification events must be logged for security auditing.

Frequency of Use

One-time setup for security-conscious learners.

Estimated adoption rate: 25-40% of active users.

Daily use during login for enrolled users.

Open Issues

Should 2FA be mandatory for learners with certification credentials?

Should we support hardware security keys (FIDO2/U2F)?

How do we handle learners in regions with poor SMS delivery?

19. Practice Coding with Code Editor (Platform)

Primary Actor

Learner

Learner: Wants to write, execute, and debug code efficiently in a professional environment on web platform.

Platform: Needs to provide secure, real-time code execution with helpful feedback.

Preconditions

Learner must be logged in to the web platform.

Learner must have access to a lesson or exercise with a coding component.

Code Editor and execution APIs must be operational.

Learner must be using desktop or laptop computer with modern web browser.

Postconditions

Code is written, executed, and results are displayed.

Progress is tracked and saved.

Learner receives feedback on their solution.

Main Success Scenario

The learner navigates to a coding exercise or lesson on the web platform.

The system loads the Code Editor with syntax highlighting for the selected language (Python/JavaScript).

The system displays:

Problem statement on the left panel

Code Editor in the center

Output console at the bottom

Starter code (if any) pre-loaded in the editor

The learner writes their code in the Code Editor.

The editor provides professional IDE features:

**IntelliSense** auto-completion

**Syntax highlighting** with color-coded keywords

**Real-time error detection** with red underlines

**Code folding** for functions and blocks

**Multiple cursor editing**

**Find and replace functionality**

**Code formatting** (Ctrl+Shift+F)

**Bracket matching**

The learner can customize editor settings:

Font size adjustment

Theme selection (dark/light mode)

Tab size configuration

Line numbers toggle

The learner clicks "Run Code" to test their solution.

The system sends the code to the secure execution API via HTTPS.

The execution API runs the code in an isolated Docker sandbox environment.

The system returns execution results:

Standard output (console.log, print statements)

Execution time (in milliseconds)

Memory usage (in MB)

Error messages with line numbers (if any)

Return values

The results are displayed in the output console below the editor with syntax highlighting.

The learner can view detailed execution metrics in an expandable panel.

If the output matches expected results, the learner clicks "Submit Solution."

The system validates the solution against all test cases (visible and hidden).

The system displays test results:

Passed test cases (✓ in green)

Failed test cases (✗ in red) with input/output comparison

Edge cases handled correctly

If all tests pass:

The system awards XP based on:

First attempt bonus (+50 XP)

Code efficiency score

Time taken to solve

Updates skill mastery metrics

Saves the code to learner's solution history

The learner sees a success message with:

Earned XP and badges

Performance comparison with other learners

Suggestions for optimization (if applicable)

Alternative Scenarios

A1. Syntax Error Detected

At Step 5, if the learner's code contains syntax errors:

Code Editor underlines the error in red with wavy line

Hovering shows tooltip:

"Syntax Error: [Description] at line [X], column [Y]"

Error panel shows detailed message with suggested fixes

The learner corrects the error and continues

A2. Runtime Error During Execution

At Step 10, if the code crashes during execution:

✗ Runtime Error: IndexError Your code encountered an issue at line 15 Stack Trace: File "main.py", line 15, in <module> print(arr[10]) IndexError: list index out of range

The learner can view full stack trace

System suggests debugging tips based on error type

A3. Execution Timeout

At Step 9, if code execution exceeds 5 seconds:

Execution Timeout Your code took longer than 5 seconds to run. Possible issues: - Infinite loop detected - Inefficient algorithm (O(n²) or worse) Suggestion: Consider optimizing your approach

The learner can review algorithm complexity

A4. Memory Limit Exceeded

At Step 10, if memory usage exceeds 512MB:

Memory Limit Exceeded Your code used more than 512MB of memory. Consider: - Reducing data structure sizes - Using generators instead of lists - Implementing streaming solutions

A5. Test Cases Failed

At Step 14-15, if some test cases fail:

Test Case 3: ✗ Failed Input: [1, 2, 3, 4, 5] Expected Output: 15 Your Output: 14 Difference: Off by 1 (check array indexing)

The learner can revise and resubmit

Hint button becomes available after 2 failed attempts

A6. Code Execution Service Unavailable

At Step 8, if the execution API is down:

Execution Service Temporarily Unavailable The code execution service is currently down. Your code has been saved as a draft. Please try again in a few minutes.

Code is auto-saved every 30 seconds

Learner can continue working offline

A7. Browser Crash or Tab Closed

If browser crashes or tab is accidentally closed:

On return, system displays:

Restored from Auto-Save Last saved: 30 seconds ago Would you like to continue where you left off? [Restore Code] [Start Fresh]

Extensions

E1. Code Snapshotting

The learner can save multiple versions of their solution

Click "Save Snapshot" button (Ctrl+S)

System stores code with timestamp: "Version 1 - 14:30:25"

Learner can compare versions side-by-side

Restore any previous version with one click

E2. Code Sharing

After successful submission, learner can share solution

Click "Share Code" generates unique URL

Other learners can view (not edit) the code

Solution appears in "Community Solutions" gallery

E3. Accessing Model Solutions

After successful submission, "View Solutions" button appears

System displays 3-5 model solutions:

**Optimal Solution** (best time/space complexity)

**Beginner-Friendly** (easiest to understand)

**Alternative Approaches** (different algorithms)

Each includes:

Big O complexity analysis

Line-by-line explanations

When to use this approach

E4. Code Execution History

Learner can view all previous runs:

Timestamp of execution

Output results

Performance metrics

Can re-run any previous version

E5. Split Screen View

Learner can enable split-screen mode:

Problem description on left

Code editor on right

Resizable panels

Useful for referencing requirements while coding

E6. Keyboard Shortcuts

Code Editor supports VS Code shortcuts:

`Ctrl+/` - Toggle line comment

`Ctrl+D` - Select next occurrence

`Alt+Up/Down` - Move line up/down

`Ctrl+Shift+K` - Delete line

`F12` - Go to definition

Full shortcut reference available in help menu

E7. Code Formatting

Learner clicks "Format Code" or presses `Ctrl+Shift+F`

System auto-formats code following PEP 8 (Python) or StandardJS style

Fixes indentation and spacing

Improves code readability

E8. Collaborative Coding (Future)

Multiple learners can work on same exercise together

Real-time cursor positions visible

Chat panel for discussion

Useful for pair programming exercises

Special Requirements

Code Editor must load within 2 seconds
Editor must support Python 3.10+ and ES6+ JavaScript
Code execution must complete within 5 seconds for standard exercises
The sandbox environment must prevent:
- File system access
- Network requests
- System command execution
- Resource exhaustion attacks
All code submissions must be encrypted during transmission (TLS 1.3)
The editor must be fully keyboard-accessible (WCAG 2.1 AA compliant)
Dark and light themes must both have sufficient contrast ratios
Editor must work on screens as small as 1024x768
Auto-save must occur every 30 seconds
Maximum code file size: 10,000 lines
Support for multiple programming languages must be extensible

Frequency of Use

This is the most frequently used feature on web platform

Average: 15-20 code executions per active session

Daily active users spend 60% of their time in Code Editor

Open Issues

Should we support additional languages (Java, C++, Ruby) in future releases?

How do we handle collaborative coding exercises without real-time sync?

Should we implement code review features for peer learning?

What's the optimal balance between sandbox security and execution speed?

Practice Coding with Blockly Editor (Mobile App)

Primary Actor

Learner

Learner: Wants an intuitive, visual way to learn programming concepts on mobile devices without typing code.

Platform: Needs to make coding accessible to beginners and younger learners through mobile-friendly interface.

Educators: Want a tool that teaches computational thinking before syntax complexity.

Preconditions

Learner must be logged in to the mobile app (iOS/Android).
Learner must have access to a lesson or exercise supporting block-based coding.
Blockly library and execution engine must be operational.
Device must have touchscreen capability.

Postconditions

Visual block program is created and executed.
Generated code (Python/JavaScript) is executed successfully.
Progress is tracked and saved.
Learner understands the underlying code structure.

Main Success Scenario

The learner navigates to a coding exercise on the mobile app.

The system detects the device type and loads the Blockly visual editor.

The system displays:

Problem statement at the top (collapsible)

Blockly workspace in the center (main area)

Block toolbox on the left side (categorized blocks)

Output console at the bottom (expandable)

Block bin/trash for removing blocks

The problem requires building a simple program (e.g., "Calculate sum of numbers in a list").

The learner taps the toolbox to browse available block categories:

Logic blocks (if/else, comparison, boolean)

Loop blocks (for, while, repeat)

Math blocks (arithmetic, random, functions)

Text blocks (string operations, concatenation)

List blocks (create, add, get, length)

Variable blocks (create, set, get)

Function blocks (define, call, return)

The learner selects a "create variable" block and names it `sum`.

The learner drags a "set variable to" block to the workspace.

The learner adds a "for each item in list" loop block.

Inside the loop, learner adds a "set sum to sum + item" block.

Blocks automatically snap together when compatible (visual feedback):

Green outline when blocks can connect

Red outline when blocks are incompatible

Magnetic snap when released near compatible blocks

The learner can:

Drag blocks with finger/stylus

Pinch to zoom for better view

Pan the workspace by dragging background

Duplicate blocks by long-press

Delete blocks by dragging to trash icon

The system shows real-time validation:

Incomplete blocks highlighted in yellow

Required connections shown with puzzle piece icons

Error indicators if logic is invalid

The learner taps "Run Code" button.

The system converts blocks to executable code (Python or JavaScript):

```python sum = 0 list = [1, 2, 3, 4, 5] for item in list: sum = sum + item print(sum) ```

The generated code is displayed in a collapsible "View Code" panel.

The learner can switch between:

Block View (visual programming)

Code View (text-based equivalent)

Split View (both simultaneously)

The system sends the generated code to the execution API.

The execution API runs the code in a secure sandbox.

The output console displays results:

Console output: `15`

Execution time: `0.02s`

Memory used: `12MB`

If output is correct, the learner taps "Submit Solution."

The system validates against test cases:

Test 1: Input `[1, 2, 3]` → Expected `6` ✓

Test 2: Input `[10, 20, 30]` → Expected `60` ✓

Test 3: Input `[]` → Expected `0` ✓

If all tests pass:

Confetti animation plays on mobile screen

Success sound effect (optional, can be muted)

XP points awarded with animation

Badge earned (e.g., "Loop Master" for completing loop exercises)

The learner sees a summary screen:

Exercise Completed!

XP earned: +30 XP

Total XP: 450 XP

Next exercise unlocked

The block program is saved to the learner's solution history.

The learner can share their block solution as an image on social media.

Alternative Scenarios

A1. Blocks Won't Connect (Type Mismatch)

At Step 10, if learner tries to connect incompatible blocks:

Blocks shake and show red outline
Tooltip displays: "❌ Cannot connect: Expected NUMBER, got TEXT"
Blocks bounce back to original position
Learner must use correct block type

A2. Missing Required Blocks

At Step 13, if program is incomplete:

⚠️ Your program is incomplete. Missing: output block

Incomplete blocks flash yellow
"Run Code" button is disabled until complete
Hint suggests which category has needed blocks

A3. Infinite Loop Detected

At Step 18, if blocks create infinite loop:

Execution is terminated after 3 seconds
System displays:
Infinite Loop Detected
Your loop ran more than 1000 times.
Check your loop condition to ensure it can exit.
Problematic loop block is highlighted in red
Learner can review loop logic

A4. Runtime Error in Generated Code

At Step 18, if execution fails:

System displays error in simple terms:
Error: Division by Zero
Your program tried to divide by 0 at this block:
[Highlights the specific block causing error]
Tip: Check if denominator can be zero
Problematic block glows red
Learner can tap block for more details

A5. Test Cases Failed

At Step 21, if some tests fail:

System shows which tests failed:
Test 2: ❌ Failed
Input: [10, 20, 30]
Expected: 60
Your Output: 50
Issue: Check your addition logic
Learner can revise blocks and retry

A6. Accidental Block Deletion

At Step 11, if learner accidentally deletes important blocks:

"Undo" button appears for 5 seconds
Tapping "Undo" restores deleted blocks
After 5 seconds, deletion is permanent
Learner can recreate blocks from toolbox

A7. Device Orientation Change

If device is rotated during exercise:

System saves current block positions
Re-layouts workspace for new orientation
Portrait mode: Toolbox becomes bottom drawer
Landscape mode: Toolbox on left sidebar
All blocks remain in same relative positions

A8. App Crashes or Closed

If app crashes or is closed:

On relaunch, system displays:
Restore Previous Session?
You were working on: "Sum Calculator"
Last saved: 2 minutes ago
[Restore] [Start New]
Auto-save occurs every 20 seconds

A9. Network Unavailable

At Step 17, if no internet connection:

📡 No Internet - Code saved locally

Execution is queued
When connection restores, code executes automatically
Learner receives notification when results are ready

Extensions

E1. Block Customization

Learner can customize block colors:

Tap block settings icon
Choose from color palette
Useful for organizing complex programs
Custom colors saved per learner

E2. Voice Input for Block Names

Learner can name variables using voice:

Tap microphone icon
Say variable name: "total score"
System creates variable with that name
Useful for accessibility

E3. Block Animation

During execution, blocks light up sequentially:

Shows program flow in real-time
Helps learners understand execution order
Speed can be adjusted (slow/normal/fast)
Can be paused at any block

E4. Tutorial Hints with Arrows

For first-time users:

Animated arrows point to next action
Speech bubbles explain each step
"Try dragging this block here 👉"
Tutorial can be skipped or replayed

E5. Block Library Favorites

Learner can mark frequently-used blocks as favorites:

Star icon on blocks
Favorites appear in "My Blocks" category
Speeds up program building

E6. Convert to Text Code

After mastering blocks, learner can transition:

Tap "Convert to Code" button
System generates Python/JavaScript
Opens in Code Editor (if on tablet/larger screen)
Learner can edit and learn text-based syntax

E7. Collaborative Block Coding

Learner can invite friend to code together:

Share session code
Both see blocks in real-time
Each user's cursor shown with name
Chat feature for discussion
Useful for pair programming

E8. Block Challenges with Timers

Timed challenges for competitive learning:

Build program in 3 minutes
Leaderboard for fastest correct solutions
Bonus XP for speed
Encourages efficiency

E9. Parent/Teacher Monitoring

Parents or teachers can view learner's block programs:

Dashboard shows completed exercises
Can view block solutions
Progress reports
Useful for tracking learning at home/school

E10. Block Export as Image

Learner can export block program as PNG:

Tap "Share" button
System generates image of blocks
Can post to social media
Useful for showcasing progress

E11. Adaptive Block Difficulty

System adjusts available blocks based on skill level:

Beginner: Basic blocks only (print, variables, simple loops)
Intermediate: Add functions, lists, conditions
Advanced: Classes, recursion, advanced data structures
Prevents overwhelming beginners with too many options

Special Requirements

Blockly editor must load within 1.5 seconds on mobile devices
Touch targets must be at least 44x44 pixels (Apple HIG standard)
Blocks must have high contrast for visibility in sunlight
Pinch-to-zoom must support 50% to 200% zoom range
Drag operations must have 150ms delay to prevent accidental moves
Block snapping must have haptic feedback (vibration) on compatible devices
Workspace must support up to 100 blocks without performance degradation
App must work offline with local execution for basic exercises
All block actions must have undo/redo support (up to 50 steps)
Block colors must be colorblind-friendly (use patterns/icons in addition to colors)
Text on blocks must be readable at minimum 16px font size
Auto-save must occur every 20 seconds
Generated code must be syntactically correct and executable
Block toolbox must be searchable for finding specific blocks quickly

Frequency of Use

Very high frequency among mobile learners (ages 8-16 primary users)
Average: 10-15 block exercises per active mobile session
70% of mobile app users prefer Blockly over text-based coding initially
Gateway to text-based programming (users transition after 3-6 months)

Open Issues

Should we support custom block creation for advanced users?
How do we handle very complex programs (100+ blocks) on small screens?
Should we implement AR (Augmented Reality) mode for 3D block visualization?
Can we integrate voice coding ("add a loop block") for hands-free operation?
Should there be a "block marketplace" where users share custom block libraries?
How do we transition users from Blockly to Code smoothly?
Should we support multiple languages (Spanish, Arabic) for block text?

Receive AI-Powered Hints

Primary Actor

Learner

Learner: Wants contextual, progressive hints that guide without giving away the complete solution.

Platform: Needs to provide intelligent assistance that enhances learning without creating dependency.

AI System (Gemini/OpenRouter/Custom model): Provides adaptive hints based on code analysis.

Preconditions

Learner must be working on an exercise.
Learner must be logged in.
AI API services (OpenRouter/Gemini/Custom model) must be operational.
Learner must have made at least one attempt at the exercise.

Postconditions

Appropriate hint is provided based on learner's current code and skill level.
Hint usage is tracked for analytics.
Learner can progress with better understanding.

Main Success Scenario

The learner is working on a coding exercise and encounters difficulty.

The learner clicks the "Get Hint" button.

The system analyzes the learner's current code and attempt history.

The system determines the learner's skill level and hint count for this exercise.

The system sends a request to the AI API with:

Problem statement

Learner's current code

Skill level

Previous hint history

Requested hint level

The AI API processes the request and generates an appropriate hint.

The AI returns a hint that:

Doesn't reveal the complete solution

Addresses the learner's specific issue

Matches the learner's comprehension level

The system displays the hint in a panel below the editor.

The hint includes:

Conceptual guidance

Suggested approach

Relevant examples (if needed)

The learner reads the hint and applies the guidance.

The system tracks the hint usage and adjusts XP rewards accordingly.

If the learner needs additional help, they can request more specific hints (progressive levels).

Alternative Scenarios

A1. No Attempt Made Yet

At Step 2, if the learner hasn't written any code:

Try writing some code first! Hints are most helpful after you've made an attempt.

The "Get Hint" button remains disabled until code is written.

A2. Maximum Hints Reached

At Step 4, if the learner has used all available hints for this exercise:

You've used all available hints. Try applying what you've learned or view the model solution.

The learner is offered the option to view the complete solution (with loss XP reward).

A3. AI Service Unavailable

At Step 6, if the AI API is down or unresponsive:

AI hints are temporarily unavailable. Here's a pre-generated hint for this problem.

The system provides a fallback hint from the database.

A4. Request Timeout

At Step 6, if the AI API doesn't respond within 10 seconds:

The hint service is taking longer than usual. Please try again.

The request is logged for admin review.

A5. Inappropriate Code Detected

At Step 5, if the learner's code contains inappropriate content:

Please ensure your code is appropriate before requesting hints.

The system doesn't send to AI and displays the message.

A6. Hint Too Advanced

At Step 7, if the AI generates a hint beyond the learner's level:

The system uses natural language processing to simplify the hint.
If simplification fails, a pre-generated hint is used instead.

Extensions

E1. Progressive Hint Levels

First hint: Conceptual guidance only
Second hint: Specific approach suggestion
Third hint: Pseudocode or example structure
Fourth hint: Partial code implementation
Fifth hint: Complete solution with explanation

E2. Code Analysis Insights

The AI identifies specific issues in the learner's code:

Logic errors
Incorrect algorithm choice
Edge case handling
The hint addresses these specific issues.

E3. Hint History

The learner can view all previously received hints.
The learner clicks "Previous Hints" to review earlier guidance.
This helps reinforce learning without requesting duplicate hints.

E4. Contextual Examples

If the hint references a concept, the system includes a link to relevant lesson content.
The learner can click to review the concept before continuing.

Special Requirements

AI hints must not reveal complete solutions directly.
Hint generation must complete within 10 seconds.
The system must track hint usage for XP calculation (fewer hints = more XP).
Hints must be appropriate for the learner's skill level.
The AI API must be rate-limited to prevent abuse.
All API communications must be encrypted.
Fallback hints must be available for all exercises.

Frequency of Use

Moderate to high frequency, especially among beginner learners.
Expected usage: 30-40% of learners per exercise.

Open Issues

Should we implement a "hint cost" using virtual currency?
How do we balance hint availability with learning independence?
Should hints be personalized based on learning style preferences?

Complete Certification Track

Primary Actor

Learner

Learner: Wants to earn a credential that validates completion of their learning path and acquired programming skills.

Platform: Needs to ensure certification standards are maintained and verifiable.

Potential Employers/Institutions: Want assurance that certifications represent genuine path completion and competency.

Content Creators: Want their learning paths to offer valuable credentials that motivate completion.

Preconditions

Learner must be logged in.
Learner must be enrolled in a learning path (from Use Case 10: Choose Learning Path).
Learner must have completed at least 95% of the learning path requirements.
The final challenge of the learning path must be unlocked.

Postconditions

Learning path is marked as 100% complete.
Learner receives a digital certificate for the completed path.
Certificate is added to learner's profile and portfolio.
Certification data is recorded in the system with timestamp.
Certificate can be verified and shared publicly.

Main Success Scenario

The learner is enrolled in a learning path (e.g., "Python Full-Stack Developer" from Use Case 10).

The learner progresses through the path by completing courses, lessons, and exercises across all tiers:

Tier 1: Foundation modules completed

Tier 2: Core concepts mastered

Tier 3: Intermediate skills acquired

Tier 4: Advanced topics finished

The system tracks progress in the learner's dashboard:

Progress bar shows: 95% complete

Status: "Final Challenge Unlocked"

The learner navigates to the learning path dashboard.

The system displays:

🎉 You're almost there! Complete the final challenge to earn your certification.

The learner clicks "Start Final Challenge."

The system displays the final challenge details:

Challenge title: "Build a Full-Stack Task Management Application"

Requirements:

Implement frontend interface
Create backend API
Database integration
User authentication
Deployment instructions

Time limit: 3-7 days (self-paced)

Submission format: GitHub repository link + deployed app URL

The learner works on the final challenge project using skills learned throughout the path.

The learner tests their application thoroughly.

The learner clicks "Submit Final Challenge."

The system prompts for submission details:

GitHub repository URL

Live deployment URL

Project description (optional)

Technologies used

The learner provides all required information and clicks "Confirm Submission."

The system validates submission:

Checks if URLs are accessible

Verifies repository contains code

Scans for plagiarism using code similarity detection

Automated Evaluation Process:

The system runs automated tests on the submitted project:

Code quality analysis (linting, formatting)
Functionality tests (API endpoints work correctly)
Security checks (no obvious vulnerabilities)
Performance benchmarks (response times acceptable)

Scoring System:

The system calculates a score based on:

Functionality: 40 points (all features work correctly)
Code quality: 30 points (clean, well-documented code)
Creativity: 15 points (innovative features, UI/UX)
Best practices: 15 points (security, performance, structure)

Minimum passing score: 70/100

If the learner achieves 70+ points:

✅ Congratulations! Your project meets certification standards.

Certificate Generation:

The system generates a digital certificate including:

Learner's full name
Learning path title: "Python Full-Stack Developer"
Completion date
Unique certificate ID (e.g., DCD-PY-2025-12345)
Platform logo and signature
QR code for verification
Path details (total hours, skills acquired)

The system displays certificate preview with animation:

Confetti effect

Achievement sound

Certificate appears with fade-in animation

The system updates learner's profile:

Badge: "Python Full-Stack Developer Certified"

Total XP bonus: +5000 XP

New level unlocked (if applicable)

Certificate added to "My Certificates" section

The system sends congratulatory email with:

Certificate PDF attachment (high-resolution, printable)

Certificate verification link

Social sharing templates

LinkedIn credential integration link

The learner can now:

Download certificate as PDF

Share on social media (LinkedIn, Twitter, Facebook)

Add to digital portfolio

Print for display

Certificate Verification:

Each certificate has unique URL: `duocodo.com/verify/DCD-PY-2025-12345`

Anyone can verify authenticity by:

Scanning QR code on certificate
Entering certificate ID on verification page

Verification page displays:

Learner name
Path completed
Completion date
" This certificate is authentic and verified by DuoCodo"

The learning path is marked as "Completed" in learner's dashboard.

The system recommends next learning paths:

"Advanced Python Development"

"DevOps for Full-Stack Developers"

"React Native Mobile Development"

The learner's portfolio automatically showcases:

The certificate

Final challenge project

All portfolio projects from the path

Alternative Scenarios

A1. Final Challenge Score Below 70

At Step 16, if score is 60-69 points:

Your project scored [X]/100. You need 70+ to pass. Review the feedback and resubmit.

The system provides detailed feedback:

Areas for improvement:
- Functionality: Missing user logout feature (-5 points)
- Code quality: Inconsistent naming conventions (-8 points)
- Security: API endpoints not protected (-7 points)

Recommendations:
- Review authentication lessons in Tier 4
- Study API security best practices
- Fix identified issues and resubmit

The learner can revise and resubmit (up to 3 attempts total).
Each attempt must wait 48 hours for review.

A2. Plagiarism Detected

At Step 13, if code similarity exceeds 80% with existing projects:

The system flags submission for manual review.
Admin investigates source of similarity.
If confirmed plagiarism:
- Submission is rejected.
- The system displays: "Your submission contains plagiarized content. Certification requires original work."
- Learner receives warning.
- Must create new project from scratch.
- Serious violations may result in temporary suspension.

A3. Submission URLs Invalid

At Step 13, if provided URLs are broken or inaccessible:

Unable to access your project. Please ensure URLs are correct and publicly accessible.

Learner must fix URLs and resubmit.
Submission is not counted as an attempt if URLs are invalid.

A4. Technical Issues During Submission

At Step 12, if submission fails due to system error:

Submission failed due to technical issues. Your work has been saved as draft.

Learner can retry submission.
Support team is notified automatically.
Deadline is extended by 24 hours if system was at fault.

A5. Maximum Attempts Reached (3 Failed Submissions)

After 3rd failed submission:

You've reached the maximum submission attempts. To earn certification, you must:

Option 1: Retake specific path modules and retry after 30 days
Option 2: Schedule mentorship session for guidance
Option 3: Restart learning path from Tier 3
The learner must choose an option to continue.

A6. Deadline Expired (If Path Has Time Limit)

If learner doesn't submit within path deadline (e.g., 6 months):

Your enrollment period has ended. To earn certification, re-enroll in the next cohort.

Progress is saved but path must be re-enrolled.
Learner can view what they completed.

A7. Learning Path Not Fully Completed

At Step 6, if learner tries to start final challenge prematurely:

Complete all path requirements before attempting final challenge. Current progress: [X]%

Shows remaining incomplete modules/exercises.
"Start Final Challenge" button remains disabled.

A8. Project Repository Private

At Step 13, if GitHub repository is set to private:

Repository must be public for evaluation. Please change repository visibility settings.

Provides instructions on making repository public.
Submission is not processed until accessible.

Extensions

E1. Certificate Levels Based on Performance

Certificates are tiered by final challenge score:

Bronze Certificate: 70-79 points (Pass)
Silver Certificate: 80-89 points (Merit)
Gold Certificate: 90-100 points (Distinction)
Certificate design and badge reflect achievement level.
Higher tiers may unlock additional benefits (e.g., featured portfolio, mentor access).

E2. LinkedIn Integration

After certificate issuance:

Learner clicks "Add to LinkedIn" button.
System auto-populates LinkedIn credential form:
- Credential name: "Python Full-Stack Developer"
- Issuing organization: DuoCodo
- Issue date: [Completion date]
- Credential ID: [Certificate ID]
- Credential URL: [Verification link]
Learner confirms and posts to LinkedIn profile.

E3. Portfolio Project Showcase

Final challenge project is featured prominently:

Public portfolio page displays:
- Project demo video/screenshots
- Live project link
- GitHub repository
- Technologies used
- Project description
Other learners can view and learn from completed projects.
Recruiters can discover learners through project showcase.

E4. Peer Recognition

Other learners can congratulate certificate earners:

"Congratulate" button sends encouragement message.
Achievement appears in community feed.
Builds motivational community culture.

E5. Multiple Learning Paths

Learners can pursue multiple certifications:

Each completed path earns separate certificate.
Dashboard shows all earned certificates.
"Collection" badges for completing related paths:
- "Web Development Master" (3 web paths completed)
- "Data Science Expert" (4 data science paths completed)

E6. Certificate Renewal/Updates

For technology-focused paths that evolve:

Certificates remain valid but note version: "Python Full-Stack Developer (2025)"
Learners notified when path is significantly updated.
Optional: Complete update modules for refreshed certificate.
Keeps certifications current with industry standards.

E7. Employer Verification Portal

Employers can verify certificates in bulk:

Upload list of certificate IDs.
System validates all certificates.
Generates report of verified credentials.
Useful for HR departments during hiring.

E8. Certificate Analytics

Learner can view certificate statistics:

How many people completed this path
Average completion time
Most common career outcomes
Salary ranges for certificate holders (if data available)

E9. Blockchain Verification (Advanced)

Certificate hash stored on blockchain:

Immutable proof of achievement.
Cannot be forged or tampered with.
Blockchain explorer link included.
Future-proof credential verification.

E10. Custom Certificate Frames

Learners can choose certificate design themes:

Professional (formal design)
Modern (colorful, vibrant)
Minimalist (clean, simple)
Personalization makes certificates more meaningful.

Special Requirements

Certificate generation must complete within 10 seconds of passing final challenge.
Certificates must be high-resolution (300 DPI) for printing.
PDF certificates must be accessible (screen reader compatible).
Certificate IDs must be cryptographically unique (collision-resistant).
Verification URLs must remain valid indefinitely (no expiration).
All certificate data must be backed up securely.
The system must handle concurrent certificate generation (100+ simultaneous).
Certificate templates must support multiple languages (English/Arabic).
Plagiarism detection must have <5% false positive rate.
Automated project evaluation must complete within 5 minutes.
Manual review (if needed) must complete within 2 business days.

Frequency of Use

Moderate frequency (20-30% of enrolled learners complete paths).
Peak certification periods: End of quarter, year-end, academic semesters.
Average time from path enrollment to certification: 3-6 months.
Completion rate varies by path difficulty and learner commitment.

Open Issues

Should certificates expire after a certain period (e.g., 3 years)?
How do we handle certificate revocation if plagiarism is discovered later?
Should we offer physical printed certificates for premium users?
Can certificates be transferable or sold (NFT certificates)?
How do we price premium certifications vs. free learning paths?
Should we partner with universities for academic credit recognition?
What level of manual review is needed vs. automated evaluation?
How do we keep certification standards consistent as platform scales?

5.4 Sequence Diagram

Sequence diagrams were created only for casual and fully-dressed use cases, as these provide sufficient interaction detail to model system behavior. Brief use cases were excluded since they describe high-level functionality without internal system collaboration.

Figure 5.5: Review And Filter System Logs

Figure 5.6: Remove Inappropriate Content

Figure 5.15: Categorize Exercise Difficulty

Figure 5.20: Validate Exercise before Publishing

Figure 5.21: Contribute to Learning Path

Figure 5.32: Share Solution

Figure 5.33: Enable Two-factor Authontecation

Figure 5.35: Practice Coding with Blockly Editor

Figure 5.37: Complete Certification Track

5.5 Class Diagram

Class diagrams are structural diagrams that show the static structure of the system, including its classes, attributes, operations, and the relationships among objects. They provide a detailed view of the system's architecture and design.

Part 1: Core User and Authentication System

This section presents the foundational classes for user management, authentication, and authorization within the DuoCodo platform. It includes user roles, profile management, and security features.

Figure 5.38: Core User and Authentication System — Figure 5.38: Class Diagram - Core User and Authentication System

Part 2: Learning Content Management

This section illustrates the classes responsible for managing educational content, including courses, lessons, exercises, and learning paths. It shows how content is structured and organized within the platform.

Figure 5.39: Learning Content Management — Figure 5.39: Class Diagram - Learning Content Management

Part 3: Submissions and Code Execution

This section demonstrates the classes that handle submission and code execution. It shows how the platform motivates and engages learners.

Figure 5.40: Progress Tracking and Gamification — Figure 5.40: Class Diagram - Submissions and Code Execution

Part 4: Exercises, Attempts and Code Analysis

This section presents the classes that enable exercises, attempts and code analysis, including comments, discussions, friend connections, sharing capabilities, and community engagement features.

Figure 5.41: Class Diagram - Exercises, Attempts and Code Analysis

Part 5: Certification and Gamification

This section shows the classes related to certification and gamification, and validation mechanisms. It demonstrates how the platform evaluates learner competency and awards credentials.

Figure 5.42: Assessment and Certification — Figure 5.42: Class Diagram - Certification and Gamification

Part 6: Administration and Platform Management

This section illustrates the classes responsible for platform administration, including system monitoring, analytics, content moderation, user management, and reporting capabilities.

Figure 5.43: Administration and Platform Management — Figure 5.43: Class Diagram - Administration and Platform Management

Key Design Patterns and Relationships

The class diagrams above illustrate several important design patterns and relationships:

Inheritance: User roles (Administrator, Content Creator, Learner) inherit from a base User class
Composition: Courses are composed of Lessons, which contain Exercises
Association: Many-to-many relationships between Learners and Courses through enrollment
Aggregation: Learning Paths aggregate multiple Courses
Dependency: Classes depend on authentication and authorization services

These diagrams provide a comprehensive view of the DuoCodo platform's architecture, showing how different components interact to deliver a complete learning experience.

Chapter 6: Database Design

6.1 Entity Relationship Diagram

Entity Relationship Diagrams (ERD) represent the data model of the DuoCodo platform, showing the entities, their attributes, and the relationships between them. This comprehensive database design ensures data integrity, efficient querying, and scalability.

Part 1: User Management and Authentication

This section presents the core entities for user management, including user accounts, roles, authentication mechanisms, and profile information. It establishes the foundation for user identity and access control.

Figure 6.1: User Management and Authentication ERD — Figure 6.1: Entity Relationship Diagram - User Management and Authentication

Part 2: Learning Content and Course Structure

This section illustrates the entities related to educational content organization, including courses, lessons, modules, exercises, and learning paths. It shows how content is structured and interconnected within the platform.

Figure 6.2: Learning Content and Course Structure ERD — Figure 6.2: Entity Relationship Diagram - Learning Content and Course Structure

Part 3: Submissions and Code Execution

This section demonstrates the entities that track submission and code execution. It shows how the platform motivates learners through gamification elements.

Figure 6.3: Progress Tracking and Gamification ERD — Figure 6.3: Entity Relationship Diagram - Submissions and Code Execution

Part 4: Exercises, Attempts and Code Analysis

This section shows the entities for exercises, attempts and code analysis. It demonstrates how the platform evaluates learner competency and issues credentials.

Figure 6.4: Assessment and Certification ERD — Figure 6.4: Entity Relationship Diagram - Exercises, Attempts and Code Analysis

Part 5: Certification and Gamification

This section presents the entities that enable certification and gamification, including comments, discussions, friend connections, notifications, sharing, and community engagement features.

Figure 6.5: Entity Relationship Diagram - Certification and Gamification

Part 6: Administration and System Management

This section illustrates the entities for platform administration, including system logs, analytics, content moderation, reports, backups, and monitoring capabilities.

Figure 6.6: Administration and System Management ERD — Figure 6.6: Entity Relationship Diagram - Administration and System Management

Database Design Principles

The ERD design follows these key principles:

Normalization: Entities are normalized to reduce data redundancy and improve data integrity
Referential Integrity: Foreign key relationships ensure data consistency across tables
Scalability: Design supports horizontal and vertical scaling for growing user base
Performance: Indexed fields and optimized relationships for efficient queries
Flexibility: Schema allows for future extensions and feature additions
Security: Sensitive data fields include encryption and access control mechanisms

These diagrams provide a comprehensive view of the DuoCodo platform's data architecture, showing how information is stored, organized, and related to support all system functionalities.

6.2 Database Schema

Database Schema represents the logical structure of the DuoCodo platform database, showing tables, columns, data types, constraints, and relationships. This detailed schema design ensures optimal performance, data integrity, and supports all platform functionalities.

Part 1: User Management and Authentication

This section presents the database tables for user management, including user accounts, roles, authentication mechanisms, and profile information. It establishes the foundation for user identity and access control with detailed field specifications.

Figure 6.7: User Management and Authentication Schema — Figure 6.7: Database Schema - User Management and Authentication

Part 2: Learning Content and Course Structure

This section illustrates the database tables related to educational content organization, including courses, lessons, modules, exercises, and learning paths. It shows how content is structured and stored within the database with proper data types and constraints.

Figure 6.8: Learning Content and Course Structure Schema — Figure 6.8: Database Schema - Learning Content and Course Structure

Part 3: Submissions and Code Execution

This section demonstrates the database tables that track learner progress, achievements, experience points (XP), badges, streaks, and leaderboard rankings. It shows how the platform stores and manages gamification elements with appropriate indexing.

Figure 6.9: Progress Tracking and Gamification Schema — Figure 6.9: Database Schema - Submissions and Code Execution

Part 4: Exercises, Attempts and Code Analysis

This section shows the database tables for quizzes, assessments, test cases, submissions, grading, and certifications. It demonstrates how the platform stores evaluation data and manages credentials with proper validation constraints.

Figure 6.10: Assessment and Certification Schema — Figure 6.10: Database Schema - Exercises, Attempts and Code Analysis

Part 5: Certification and Gamification

This section presents the database tables that enable social interactions, including comments, discussions, friend connections, notifications, sharing, and community engagement features with optimized query structures.

Figure 6.11: Database Schema - Certification and Gamification

Part 6: Administration and System Management

This section illustrates the database tables for platform administration, including system logs, analytics, content moderation, reports, backups, and monitoring capabilities with appropriate data retention policies.

Figure 6.12: Administration and System Management Schema — Figure 6.12: Database Schema - Administration and System Management

Database Schema Specifications

The database schema implementation follows these key specifications:

Data Types: Appropriate data types chosen for optimal storage and performance
Constraints: Primary keys, foreign keys, unique constraints, and check constraints ensure data integrity
Indexing: Strategic indexes on frequently queried columns for optimal performance
Normalization: Tables normalized to 3NF (Third Normal Form) to eliminate redundancy
Referential Integrity: Foreign key relationships maintain consistency across related tables
Security: Sensitive fields include encryption specifications and access control measures
Scalability: Schema design supports partitioning and sharding for future growth
Backup Strategy: Tables include timestamp fields for incremental backup operations

This detailed schema provides the implementation blueprint for the DuoCodo platform's database, ensuring robust data management and optimal query performance across all system components.

Chapter 7: User Interface

7.1 Authentication Screens

Register Screen — Figure 7.2: Registration Screen

Password Screen — Figure 7.4: Password Entry Screen

New Password Screen — Figure 7.5: New Password Creation Screen

7.2 Main Dashboard

Figure 7.8: Interface with Collapsed Sidebar

Quiz MCQ — Figure 7.11: Multiple Choice Quiz

Quiz Code — Figure 7.12: Code Quiz Interface

Quiz Completed — Figure 7.13: Quiz Completion Screen

7.3 Learning Paths

Figure 7.16: Dashboard with Filtration Options

7.4 Progress Tracking & Analytics

Progress and Analysis — Figure 7.17: Progress & Analysis Dashboard

7.5 Theme Options

Faculty of Computers and Information

DuoCodo

Table of Contents ​

List of Figures ​

List of Tables ​

Chapter 1: Project Overview ​

1.1 Main Idea ​

1.2 Project Scope ​

1. Comprehensive Curriculum & Content ​

2. Intelligent Code Editor ​

3. Dynamic Interactive Exercises ​

4. Advanced Gamification System ​

5. Personalized Progress Ecosystem ​

6. Accessibility & Scalability ​

1.3 Problem Statement ​

1.4 Solution Approach ​

A. Structured Yet Adaptive Onboarding ​

B. Contextual Practice Engine ​

C. Gamification × Depth ​

D. Personalized Reinforcement ​

1.5 Project Objectives ​

1. Deliver a Progressive, Mastery-Based Curriculum ​

2. Build an Intelligent, Adaptive Practice Ecosystem ​

3. Gamify Learning with Depth & Nuance ​

4. Enable Hyper-Personalized Tracking ​

5. Ensure Accessibility & Scalability ​

Chapter 2: Project Background ​

2.1 Project Background ​

2.2 Related Work ​

Elzero Web School ​

Codeforces ​

CodeChef ​

HackerRank ​

LeetCode ​

TopCoder ​

AtCoder ​

CodinGame ​

CodeCombat ​

Codewars ​

CheckiO ​

2.3 Summary ​

Chapter 3: Feasibility and Project Planning ​

3.1 Feasibility Study ​

3.1.1 Technical Feasibility ​

3.1.2 Organizational Feasibility ​

3.1.3 Economic Feasibility ​

3.2 Risk Management ​

3.2.1 Technical Risks ​

3.2.2 Operational Risks ​

3.2.3 Legal & Compliance Risks ​

3.3 Project plan ​

3.4 Gantt Chart ​

Chapter 4: System Analysis ​

4.1 Function Requireements ​

4.1.1 User Management System ​

4.1.2 Learning Management System ​

4.1.3 Code Editor and Execution Environment ​

4.1.4 Interactive Exercise System ​

4.1.5 Gamification System ​

4.1.6 Progress Tracking and Analytics ​

4.1.7 AI-Powered Features ​

4.1.8 Content Management System ​

4.1.9 System Administration ​

4.1.10 Integration and API Features ​

4.1.11 Security and Privacy ​

4.2 Non-Function Requirements ​

4.2.1 Performance ​

4.2.2 Availability ​

4.2.3 Scalability ​

4.2.4 Reliability ​

4.2.5 Interoperability ​

4.2.6 Usability ​

4.2.7 Maintainability ​

4.2.8 Recovery ​

4.3 Functional Decomposition ​

Chapter 5: System Architecture ​

5.1 Actor-goal List ​

5.2 Use Cases Diagram ​

5.3 Use Cases Format ​

5.3.1 Administrator Use Cases ​

Table of Contents

List of Figures

List of Tables

Chapter 1: Project Overview

1.1 Main Idea

1.2 Project Scope

1. Comprehensive Curriculum & Content

2. Intelligent Code Editor

3. Dynamic Interactive Exercises

4. Advanced Gamification System

5. Personalized Progress Ecosystem

6. Accessibility & Scalability

1.3 Problem Statement

1.4 Solution Approach

A. Structured Yet Adaptive Onboarding

B. Contextual Practice Engine

C. Gamification × Depth

D. Personalized Reinforcement

1.5 Project Objectives

1. Deliver a Progressive, Mastery-Based Curriculum

2. Build an Intelligent, Adaptive Practice Ecosystem

3. Gamify Learning with Depth & Nuance

4. Enable Hyper-Personalized Tracking

5. Ensure Accessibility & Scalability

Chapter 2: Project Background

2.1 Project Background

2.2 Related Work

Elzero Web School

Codeforces

CodeChef

HackerRank

LeetCode

TopCoder

AtCoder

CodinGame

CodeCombat

Codewars

CheckiO

2.3 Summary

Chapter 3: Feasibility and Project Planning

3.1 Feasibility Study

3.1.1 Technical Feasibility

3.1.2 Organizational Feasibility

3.1.3 Economic Feasibility

3.2 Risk Management

3.2.1 Technical Risks

3.2.2 Operational Risks

3.2.3 Legal & Compliance Risks

3.3 Project plan

3.4 Gantt Chart

Chapter 4: System Analysis

4.1 Function Requireements

4.1.1 User Management System

4.1.2 Learning Management System

4.1.3 Code Editor and Execution Environment

4.1.4 Interactive Exercise System

4.1.5 Gamification System

4.1.6 Progress Tracking and Analytics

4.1.7 AI-Powered Features

4.1.8 Content Management System

4.1.9 System Administration

4.1.10 Integration and API Features

4.1.11 Security and Privacy

4.2 Non-Function Requirements

4.2.1 Performance

4.2.2 Availability

4.2.3 Scalability

4.2.4 Reliability

4.2.5 Interoperability

4.2.6 Usability

4.2.7 Maintainability

4.2.8 Recovery

4.3 Functional Decomposition

Chapter 5: System Architecture

5.1 Actor-goal List

5.2 Use Cases Diagram

5.3 Use Cases Format

5.3.1 Administrator Use Cases

5.3.2 Content Creator Use Cases

5.3.3 Learner Use Cases