Chapter 5: System Architecture

5.3 Use Cases Formats

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 Use Cases Formats
• Administrator Use Cases
  • Brief Format Use Cases
  • Casual Format Use Cases
  • Fully Dressed Format Use Cases
• Content Creator Use Cases
  • Brief Format Use Cases
  • Casual Format Use Cases
  • Fully Dressed Format Use Cases
• Learner Use Cases
  • Brief Format Use Cases
  • Casual Format Use Cases
  • Fully Dressed Format Use Cases

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.

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Casual Format Use Cases

4. Manage User Accounts

Actor: Administrator

Main Success Scenario:

1. The administrator logs into the admin dashboard.
2. The administrator navigates to the "User Management" section.
3. The system displays a searchable, filterable user list with columns:
   • Username
   • Email
   • Role (Learner/Content Creator/Admin)
   • Account status (Active/Suspended/Deactivated)
   • Registration date
   • Last login
   • Total XP/Activity level
4. The administrator can search by username, email, or user ID.
5. The administrator can filter by:
   • Role type
   • Account status
   • Registration date range
   • Activity level (active/inactive)
6. The administrator selects a specific user to view details.
7. The system displays comprehensive user profile:
   • Personal information
   • Enrolled courses
   • Progress statistics
   • Activity history
   • Violation reports (if any)
8. The administrator can perform actions:
   • Edit user information
   • Reset password
   • Change account status
   • Adjust user role
   • View security logs
9. The administrator makes necessary changes and clicks "Save."
10. The system updates user information and logs the administrative action.
11. The affected user receives notification of account changes (if applicable).

Alternative Scenarios:

A1. User Not Found

• At Step 4, if search returns no results:
  • The system displays: "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:
  • The system displays: "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:
  • The system displays: "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

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5. Assign User Roles

Actor: Administrator

Main Success Scenario:

1. The administrator navigates to "Role Management" in the admin panel.
2. The system displays available roles:
   • Learner (default)
   • Content Creator
   • Mentor/Reviewer
   • Administrator
   • Super Administrator
3. The administrator searches for a specific user.
4. The administrator selects the user and clicks "Change Role."
5. The system displays current role and available role options.
6. The administrator selects the new role from the dropdown.
7. If promoting to Content Creator or higher, the system prompts:
   • "This role grants elevated permissions. Confirm you want to proceed?"
8. The administrator confirms the role change.
9. The system updates the user's role and permissions.
10. The system sends notification to the user:
    • "Your account role has been updated to [New Role]. You now have access to [features]."
11. The system logs the role change with timestamp and admin identifier.
12. 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:
  • The system displays: "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:
  • The system displays: "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:
  • The system warns: "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:
  • The system warns: "This user has [X] published courses. Demoting will affect content management. Reassign content?"
  • Admin must decide how to handle existing content.

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6. Monitor Platform Analytics

Actor: Administrator

Main Success Scenario:

1. The administrator logs into the admin dashboard.
2. The administrator navigates to "Platform Analytics."
3. 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
4. The administrator can customize the date range (last 7 days, 30 days, 90 days, custom).
5. The administrator can filter by:
   • User segment (learners, content creators)
   • Course categories
   • Learning paths
   • Device types (desktop, mobile)
6. 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)
7. The administrator can drill down into specific metrics:
   • Clicks on "Course Completion Rate"
   • System shows breakdown by course, difficulty level, and time period
8. The administrator identifies trends:
   • Notice a drop in engagement on weekends
   • See spike in mobile usage
   • Identify popular learning paths
9. The administrator can export reports in multiple formats:
   • PDF (executive summary)
   • Excel (detailed data)
   • CSV (raw data)
10. The administrator schedules automated reports:
    • Weekly summary email
    • Monthly executive dashboard
    • Quarterly performance review
11. The system saves admin's preferred dashboard configuration.

Alternative Scenarios:

A1. Insufficient Data

• At Step 3, if platform is newly launched with minimal data:
  • The system displays: "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:
  • The system displays progress indicator: "Loading analytics... This may take a minute for large datasets."

A3. Export Limit Exceeded

• At Step 9, if requesting very large data export:
  • The system warns: "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:
  • The system displays: "Real-time data temporarily unavailable. Showing last cached data from [timestamp]."

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7. Review and Filter System Logs

Actor: Administrator

Main Success Scenario:

1. The administrator navigates to "System Logs" in the admin panel.
2. 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)
3. The administrator selects "Security Logs."
4. The system displays recent security events with details:
   • Timestamp
   • Event type
   • User involved
   • IP address
   • Action taken
   • Outcome (success/failure)
5. The administrator can filter logs by:
   • Date/time range
   • Event severity (info, warning, error, critical)
   • User or IP address
   • Event type
6. The administrator searches for specific events (e.g., "failed login attempts from IP X").
7. The system highlights matching log entries.
8. The administrator can expand log entries for detailed information:
   • Full error stack trace
   • Request parameters
   • System state at time of event
9. The administrator can export filtered logs for analysis.
10. The system allows the administrator to flag logs for follow-up investigation.
11. 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:
  • The system displays: "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:
  • The system alerts: "Warning: Log storage at 85% capacity. Archive or delete old logs to prevent data loss."

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8. Remove Inappropriate Content

Actor: Administrator

Main Success Scenario:

1. The administrator receives a content flagging notification or browses flagged content.
2. The administrator navigates to "Content Moderation" section.
3. The system displays pending moderation queue:
   • Flagged courses
   • Flagged exercises
   • Flagged forum posts
   • Flagged solutions
   • Reported user profiles
4. Each item shows:
   • Content preview
   • Reporter information
   • Reason for flag
   • Timestamp
   • Content creator
5. The administrator selects a flagged item to review.
6. The system displays the full content with context.
7. The administrator evaluates against platform guidelines:
   • Offensive language
   • Plagiarized content
   • Inappropriate images
   • Misleading information
   • Spam or advertising
   • Copyright violations
8. If content violates guidelines, the administrator chooses action:
   • Remove content immediately
   • Require revision by creator
   • Issue warning to creator
   • Suspend creator account
9. The administrator selects "Remove Content."
10. The system prompts for removal reason (required for transparency).
11. The administrator enters: "Contains plagiarized code from [source]. Violates copyright policy."
12. The system removes the content from public view.
13. The system notifies the content creator:
    • "Your content '[Title]' has been removed for: [Reason]. You may appeal this decision or create compliant content."
14. If repeat violation, the system automatically escalates to account suspension.
15. The system logs all moderation actions for audit trail.
16. 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:
  • System alerts: "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

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9. Issue User Warnings

Actor: Administrator

Main Success Scenario:

1. The administrator identifies a policy violation (minor infraction).
2. The administrator navigates to the user's account.
3. The administrator clicks "Issue Warning."
4. 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
5. 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"
6. The administrator selects "Send Warning."
7. The system records the warning on user's account.
8. The system sends notification to the user:
   • Email and in-platform notification
   • Clear explanation of violation
   • Link to relevant policy
   • Consequences of repeated violations
9. The warning appears on user's account record (visible to admins only).
10. The system tracks warning count:
    • 1st warning: Notice only
    • 2nd warning: 24-hour activity restriction
    • 3rd warning: 7-day suspension
    • 4th warning: Permanent ban
11. User can acknowledge warning or submit an appeal.
12. 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"
  • System suggests immediate suspension instead of warning
  • Administrator can proceed with suspension instead

A3. Pattern of Violations

• At Step 3, if user has prior warnings:
  • System displays: "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

17. Design Learning Path

Primary Actor: Administrator

Stakeholders and Interests:

• 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:

1. The administrator navigates to "Learning Path Management" in the admin panel.
2. The administrator clicks "Create New Learning Path."
3. 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)
4. The administrator enters the basic path information.
5. 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)
6. 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
7. 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
8. 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
9. The system visualizes dependencies as a flowchart.
10. 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
11. 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)
12. The system displays assignment summary showing which creators are assigned where.
13. 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")
14. 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
15. The administrator defines checkpoint passing criteria.
16. 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
17. 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
18. 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)
19. 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)
20. The administrator adds preview content (free introductory lessons).
21. The administrator reviews the complete path structure.
22. The administrator clicks "Validate Learning Path."
23. 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
24. The system reports validation results.
25. If validation passes, the administrator sees: "✓ Learning path structure validated successfully."
26. 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)
27. The administrator selects "In Development" to activate content creation.
28. 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
29. Assigned creators receive task assignments in their dashboards.
30. The system creates a project management view showing:
    • Content creation progress for each tier
    • Creator task statuses
    • Upcoming deadlines
    • Bottlenecks or delays
31. The administrator can monitor progress and send reminders.
32. 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:
  • System displays: "✗ 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:
  • System displays: "⚠ 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:
  • System warns: "⚠ 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:
  • System calculates total content hours needed vs. creator availability
  • Displays: "⚠ 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:
  • System warns: "⚠ 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:
  • System warns: "⚠ 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:
  • System displays: "⚠ 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:
  • System warns: "⚠ [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:
  • System calculates total cost based on creator rates and content requirements
  • If budget is exceeded: "⚠ 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?

Content Creator Use Cases

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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.

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Casual Format Use Cases

5. Register Account

Actor: Content Creator

Main Success Scenario:

1. The Content Creator navigates to the "Sign Up" page of the platform.
2. The Content Creator selects the "Content Creator" role from account type options.
3. The Content Creator provides required details:
   • Full name
   • Email address
   • Password (with confirmation)
   • Username
   • Resume/CV upload
4. The Content Creator agrees to Terms and Conditions and submits the form.
5. The system validates input (email format, password strength, username uniqueness, resume/CV format).
6. The system sends a verification email to the provided address.
7. The Content Creator clicks the OTP in the email.
8. Admin activates the account after reviewing the resume/CV.
9. The system redirects to the login page.
10. 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."

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6. Login to System

Actor: Content Creator

Main Success Scenario:

1. The content creator navigates to the login page.
2. The content creator enters their email and password.
3. The content creator clicks "Login."
4. The system validates credentials.
5. The system authenticates the content creator and redirects to the dashboard.
6. 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."

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7. Create Course

Actor: Content Creator

Main Success Scenario:

1. The content creator logs into the platform.
2. The content creator navigates to "Content Management" section.
3. The content creator clicks "Create New Course."
4. 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
5. The content creator fills in all required information.
6. The content creator organizes the course into modules:
   • Adds module titles
   • Orders modules sequentially
   • Assigns estimated time per module
7. The content creator clicks "Create Course."
8. The system validates all inputs and generates a unique course ID.
9. The system creates the course structure and saves it as a draft.
10. The system displays: "Course created successfully! Now you can add lessons and exercises."
11. 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:
  • The system displays: "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:
  • The system displays: "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:
  • The system displays: "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:
  • The system displays: "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:

1. The content creator selects an existing course from their dashboard.
2. The content creator selects a module within the course.
3. The content creator clicks "Add New Lesson."
4. The system displays the lesson creation interface with sections:
   • Lesson title
   • Lesson objectives
   • Content type selection (Text/Video)
   • Estimated completion time
5. The content creator enters the lesson title and objectives.
6. The content creator creates multi-format content:
   • Writes explanatory text with rich formatting
   • Uploads or embeds video tutorial
7. The content creator adds code snippets with syntax highlighting.
8. The content creator sets lesson order within the module.
9. The content creator can mark the lesson as:
   • Draft (not visible to learners)
   • Published (immediately available)
   • Scheduled (available on specific date)
10. The content creator clicks "Save Lesson."
11. The system validates content and saves the lesson.
12. The system displays: "Lesson saved successfully!"

Alternative Scenarios:

A1. Video Upload Fails

• At Step 6, if video upload encounters an error:
  • The system displays: "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:
  • The system warns: "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:

1. The content creator is editing a lesson.
2. The content creator clicks "Add Media" in the content editor.
3. The system displays media upload options:
   • Upload video file
   • Embed YouTube/Vimeo link
   • Upload images/diagrams
   • Add audio explanations
4. The content creator selects "Upload Video."
5. The content creator selects a video file from their device.
6. The system validates file size (max 500MB) and format (MP4, WebM).
7. The system displays upload progress bar.
8. The video uploads successfully to cloud storage.
9. The system generates a video player preview.
10. The content creator positions the video within the lesson content.
11. The content creator adds captions or transcripts (optional).
12. The content creator saves the lesson with embedded media.
13. The system confirms: "Media added successfully!"

Alternative Scenarios:

A1. File Size Exceeds Limit

• At Step 6, if the video is larger than 500MB:
  • The system displays: "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:
  • The system displays: "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:
  • The system displays: "Unable to embed this link. Please verify the URL and privacy settings."

---

10. Localize Content

Actor: Content Creator

Main Success Scenario:

1. The content creator selects a published course or lesson.
2. The content creator clicks "Add Translation."
3. The system displays available languages (Arabic, English).
4. The content creator selects the target language (e.g., Arabic).
5. The system creates a duplicate content template with original text.
6. The content creator translates:
   • Lesson titles and descriptions
   • Content paragraphs
   • Code comments
   • Exercise instructions
7. The content creator adjusts formatting for RTL (right-to-left) if translating to Arabic.
8. The content creator can use AI-assisted translation for initial draft.
9. The content creator reviews and refines the AI-generated translation.
10. The content creator saves the localized version.
11. The system marks the content as available in multiple languages.
12. Learners can now switch between languages when viewing the content.

Alternative Scenarios:

A1. AI Translation Unavailable

• At Step 8, if AI service is down:
  • The system displays: "AI translation is temporarily unavailable. Please translate manually."

A2. Incomplete Translation

• At Step 10, if some sections remain untranslated:
  • The system warns: "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:

1. The content creator is creating or editing an exercise.
2. 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)
3. The content creator selects the appropriate difficulty.
4. The system displays difficulty criteria to guide selection.
5. The content creator assigns skill tags (e.g., "loops", "arrays", "recursion").
6. The system estimates average completion time based on difficulty.
7. The content creator can test the exercise themselves to verify difficulty.
8. The content creator saves the categorization.
9. 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:
  • The system displays: "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:

1. The content creator navigates to "My Courses."
2. The content creator selects a published course.
3. The content creator identifies content to update (lesson, exercise, video).
4. The content creator clicks "Edit."
5. The system loads the content in edit mode.
6. The content creator makes changes:
   • Updates outdated information
   • Fixes errors or typos
   • Improves explanations
   • Adds new examples
7. The content creator saves changes.
8. The system creates a new version and maintains version history.
9. If the course has active learners, the system displays: "[X] students are enrolled. Notify them of updates?"
10. The content creator chooses to send update notification.
11. Enrolled learners receive: "[Course Name] has been updated with new content!"
12. The system logs all changes for audit trail.

Alternative Scenarios:

A1. Breaking Changes

• At Step 6, if changes affect exercise solutions or grading:
  • The system warns: "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:
  • The system displays: "[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:

1. The content creator navigates to "Course Management" dashboard.
2. The content creator selects a lesson in specific course to review submissions.
3. The system displays recent submissions for the creator's lesson.
4. The content creator filters by:
   • Execution metrics (time/memory)
   • Test case pass rate
   • Submission date
5. The content creator selects a student submission to review.
6. The system displays:
   • Student information (anonymous option available)
   • Problem statement
   • Student's code solution
   • Test case results
   • Execution metrics
7. The content creator reviews the code for:
   • Correctness
   • Code quality and style
   • Efficiency
   • Best practices
8. The content creator provides written feedback.
9. The content creator clicks "Submit Review."
10. The system saves the review and updates the student's grade.
11. The student receives notification with feedback.

Alternative Scenarios:

A1. Auto-Graded Exercise

• At Step 4, if the exercise is automatically graded:
  • The system displays: "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:

1. The content creator selects a course from their dashboard.
2. The content creator clicks "Edit Course Structure."
3. The system displays the course outline with all modules and lessons.
4. 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)
5. The content creator sets prerequisites:
   • Marks lessons that must be completed before others unlock
   • Creates skill dependencies
6. The content creator saves the new structure.
7. The system validates that prerequisites don't create circular dependencies.
8. The system updates the course structure.
9. If students are enrolled, the system adjusts their progress tracking.
10. The system displays: "Course structure updated successfully!"

Alternative Scenarios:

A1. Circular Dependency Detected

• At Step 7, if prerequisites create a loop:
  • The system displays: "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:
  • The system warns: "[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

Stakeholders and Interests:

• 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:

1. The content creator navigates to a course lesson.
2. The content creator clicks "Add Exercise."
3. The system displays the exercise creation wizard with tabs:
   • Problem Details
   • Test Cases
   • Model Solution
   • Hints
   • Metadata
4. 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)
5. The content creator writes starter code template (optional).
6. 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
7. The content creator marks 2-3 test cases as public (visible to learners).
8. The content creator marks remaining cases as hidden (for final validation).
9. 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)
10. The content creator runs the model solution against all test cases.
11. The system validates that the model solution passes all test cases.
12. 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)
13. 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
14. The content creator clicks "Save as Draft."
15. The system saves the exercise in draft status.
16. The system displays: "Exercise saved successfully! Proceed to validation when ready."
17. The content creator can:
    • Continue editing
    • Submit for validation (goes to Use Case 16)
    • Delete draft
18. The content creator clicks "Submit for Validation."
19. 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:
  • The system displays: "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:
  • The system displays: "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:
  • The system displays: "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

Stakeholders and Interests:

• 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:

1. The content creator has completed exercise creation (from Use Case 15).
2. The content creator clicks "Submit for Validation."
3. The system displays: "Beginning comprehensive validation... This may take 30-60 seconds."
4. 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
5. The system confirms: "✓ Model solution passes all [X] test cases."
6. 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
7. The system reports: "✓ Test cases provide adequate coverage."
8. 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
9. The system reports: "✓ Problem statement is clear and complete."
10. 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
11. The system reports: "✓ Estimated difficulty matches assigned level (Intermediate)."
12. 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
13. The system reports: "✓ Hints provide appropriate guidance without spoiling solution."
14. 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
15. The system reports: "✓ Exercise meets security and fairness standards."
16. The system compiles a comprehensive validation report showing all checks.
17. The system displays final status: "✓ Validation Complete: PASSED"
18. The content creator reviews the full validation report.
19. 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)
20. The content creator clicks "Assign for Peer Review."
21. The system displays peer reviewer selection interface.
22. 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
23. The content creator selects reviewers (1-3 reviewers).
24. The system sends notifications to selected reviewers:
    • "You've been assigned to review exercise '[Title]'. Please complete within 3-5 business days."
25. The exercise is added to each reviewer's review queue.
26. The system sets review deadline (5 business days from assignment).
27. The system displays to creator: "Exercise assigned for peer review. You'll be notified when reviews are complete."
28. The exercise status changes to "Under Peer Review."
29. The creator receives a confirmation summary:
    • Validation results
    • Assigned reviewers
    • Expected review completion date
30. 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:
  • System displays: "✗ 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:
  • System warns: "⚠ 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:
  • System suggests: "⚠ 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:
  • System reports: "⚠ 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:
  • System displays: "✗ 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:
  • System warns: "⚠ 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:
  • System displays: "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:
  • System displays: "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:
  • System warns: "⚠ 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

Stakeholders and Interests:

• 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:

1. The content creator receives a notification: "You've been assigned to create content for '[Path Name]' - [Tier/Module Name]."
2. The content creator navigates to "My Assignments" in their dashboard.
3. 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
4. The content creator reviews the requirements and clicks "Accept Assignment."
5. The system creates a task board for the creator showing:
   • Checklist of required content items
   • Progress tracker (0% complete)
   • Deadline countdown
6. Step 1: Plan Content Structure
   • The creator outlines topics to cover in each lesson
   • Maps exercises to specific learning objectives
   • Designs project requirements
7. The creator can request clarification from the administrator if objectives are unclear.
8. 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
9. The system tracks completed lessons and updates progress (e.g., 30% complete).
10. 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
11. The system tracks completed exercises and updates progress (e.g., 60% complete).
12. 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
13. The creator can preview the entire tier as a learner would experience it.
14. 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
15. The creator makes any necessary revisions.
16. 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?"
17. The creator confirms submission.
18. The system notifies the administrator: "[Creator Name] has submitted content for '[Tier Name]' in '[Path Name]'. Ready for review."
19. The system changes the tier status to "Under Administrator Review."
20. The creator's task board shows "Awaiting Review" status.
21. Administrator Review Phase:
    • Administrator reviews all content (separate use case)
    • Administrator can approve, request revisions, or reject
22. 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
23. If revisions requested:
    • Creator receives detailed feedback with specific issues
    • Creator makes requested changes
    • Creator resubmits (returns to Step 17)
24. 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 (if applicable)

• 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? Primary Actor: Content Creator

Stakeholders and Interests:

• Content Creator: Wants to design a coherent, progressive curriculum that effectively builds skills.
• Learners: Need a clear, logical progression that builds on previous knowledge.
• Platform: Needs well-structured paths that improve learning outcomes and retention.

Preconditions:

• Content creator must be logged in with advanced privileges.
• Multiple courses and lessons must already exist in the system.
• Content creator must have curriculum design training or certification.

Postconditions:

• A complete learning path is created with prerequisite dependencies.
• Path is organized into skill tiers with clear progression.
• Path can be discovered and followed by learners.
• Path analytics tracking is enabled.

Main Success Scenario:

1. The content creator navigates to "Learning Paths" management section.
2. The content creator clicks "Create New Learning Path."
3. The system displays the path creation wizard with fields:
   • Path name (e.g., "Python Full-Stack Developer")
   • Path description and objectives
   • Target audience (beginners, intermediate, advanced)
   • Estimated total duration
   • Career outcomes or certifications earned
4. The content creator enters the basic path information.
5. Step 1: Define Skill Tiers
   • The system displays a visual canvas for organizing content
   • The content creator creates skill tiers (levels) for example:
     • 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)
6. The content creator assigns courses and lessons to each tier.
7. Step 2: Set Prerequisites
   • For each course/lesson, the creator defines:
     • Required prior courses (hard prerequisites)
     • Recommended prior knowledge (soft prerequisites)
     • Minimum skill mastery percentages needed
8. The system visualizes dependencies as a flowchart.
9. Step 3: Create Checkpoints
   • The content creator adds assessment checkpoints:
     • End-of-tier quizzes
     • Skill validation exercises
10. The content creator defines checkpoint passing criteria (e.g., 70% score, project approval).
11. Step 4: Configure Adaptive Elements
    • The creator sets rules for adaptive progression:
      • 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
12. Step 5: Add Milestones and Rewards
    • The creator defines milestones (25%, 50%, 75%, 100% completion)
    • Each milestone awards:
      • Badges (e.g., "Python Fundamentals Master")
      • XP bonuses
      • Unlocked content or features
13. Step 6: Create Path Roadmap Visualization
    • The system generates an interactive visual roadmap
    • Shows learner's current position, completed modules, upcoming content
    • Highlights optional branches and specializations
14. The content creator reviews the complete path structure.
15. The content creator clicks "Validate Learning Path."
16. System Validation Process:
    • Checks for circular dependencies (A requires B, B requires A)
    • Verifies all content exists and is published
    • Ensures no orphaned content (unreachable modules)
    • Validates prerequisite logic
    • Estimates total time commitment is reasonable
17. The system reports: "✓ Learning path structure validated successfully."
18. Step 7: Set Enrollment Options
    • The creator configures:
      • Free or paid enrollment
      • Entry requirements (diagnostic quiz, prior experience)
      • Maximum concurrent enrollments
      • Certification options upon completion
19. The content creator writes a compelling path overview for learners:
    • What you'll learn
    • Career opportunities
    • Success stories from graduates
20. The content creator adds preview content (free introductory lessons).
21. The content creator sets the path status:
    • Draft (visible only to creator)
    • Beta (open to limited testers)
    • Published (publicly available)
22. The content creator selects "Publish."
23. The system publishes the learning path and makes it discoverable.
24. The system displays: "Learning path '[Path Name]' published successfully! [X] learners can now discover it."
25. The path appears in the catalog with enrollment call-to-action.

Alternative Scenarios:

A1. Circular Dependency Detected

• At Step 16, if prerequisites create a loop:
  • System displays: "✗ Circular dependency detected: Course A → Course B → Course C → Course A"
  • Shows visual diagram of the problematic chain
  • Validation fails; creator must restructure
  • Suggests which prerequisite to remove to break cycle

A2. Orphaned Content

• At Step 16, if some content is unreachable:
  • System warns: "⚠ The following modules have no path to reach them: [List]"
  • Creator can connect them or mark as optional side content

A3. Unrealistic Time Commitment

• At Step 16, if total estimated time is excessive:
  • System warns: "⚠ This path requires ~500 hours. Consider breaking into multiple paths or reducing content."
  • Shows average learner completion rates for paths of similar length
  • Creator can proceed or revise

A4. Missing Prerequisites

• At Step 8, if advanced content lacks foundation:
  • System suggests: "Course [X] covers advanced topics but lacks prerequisites. Add foundational courses or adjust tier placement."
  • Creator receives recommendations for appropriate prerequisites

A5. Content Not Published

• At Step 16, if referenced content is still in draft:
  • System displays: "✗ Cannot publish path. The following content is unpublished: [List]"
  • Creator must publish content or remove from path
  • Path can be saved as draft

A6. Insufficient Checkpoints

• At Step 9-10, if few or no checkpoints exist:
  • System warns: "⚠ This path lacks assessment checkpoints. Learners may progress without adequate skill validation."
  • Recommends adding checkpoints every 20-30 hours of content

A7. Duplicate Path

• At Step 23, if a very similar path exists:
  • System displays: "A similar learning path exists: '[Path Name]'. This may confuse learners. Consider differentiating or merging."
  • Shows comparison of content overlap
  • Creator can proceed or revise A8. Beta Testing Feedback
• At Step 21, if creator chooses "Beta":
  • System limits enrollment to 50-100 testers
  • Collects detailed feedback on path clarity and difficulty
  • After 30 days or 25+ completions, creator reviews feedback
  • Creator adjusts path before full publication

A9. Enrollment Requirements Too Restrictive

• At Step 18, if entry requirements are very high:
  • System warns: "⚠ Entry requirements may limit enrollment. Estimated eligible learners: [X]"
  • Creator can adjust or proceed with niche audience

A10. Missing Career Outcomes

• At Step 19, if career information is vague:
  • System prompts: "Learners want to know career outcomes. Add job roles, salary ranges, or skills validated."
  • Provides templates and industry data

Extensions:

E1. Path Branching

• Creator 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 and outcomes

E2. Collaborative Path Design

• Multiple creators can co-author a learning path:
  • Each contributes courses in their expertise area
  • System tracks contributions and splits analytics
  • Coordinators approve structural changes

E3. Path Cloning and Customization

• Creator can clone an existing successful path:
  • Modify for different audience (teens vs. adults)
  • Translate to different language
  • Add organization-specific content
  • Original creator receives attribution

E4. Dynamic Path Updates

• Path can be updated without disrupting active learners:
  • New content added at end or as optional modules
  • Deprecated content marked but remains accessible
  • Learners notified of updates with opt-in to new version

E5. Path Analytics Dashboard

• After publication, creator 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)
• Data informs path improvements

E6. Certification Integration

• Path can include official certification:
  • Final comprehensive exam
  • Portfolio review by mentors
  • Interview simulation
  • Digital credential issued upon completion
  • Verified on blockchain for authenticity

E7. Corporate/Academic Partnerships

• Paths designed for institutions:
  • Aligns with specific curriculum standards
  • Includes institutional branding
  • Provides instructor dashboard for monitoring groups
  • Exports transcripts and grades

Special Requirements:

• The visual path designer must support drag-and-drop for organizing content.
• The system must prevent circular dependencies through real-time validation.
• Path roadmaps must be responsive and accessible on mobile devices.
• 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.
• The system must cache complex prerequisite graphs for performance.

Frequency of Use:

• Lower frequency; typically 5-10 comprehensive paths per creator over time.
• High usage during initial platform launch and major curriculum updates.
• Moderate ongoing maintenance for path updates.

Open Issues:

• Should learning paths have expiration dates or version numbers?
• How do we handle learners who start a path that's later significantly updated?
• Should there be limits on path length or complexity?
• Can AI assist in recommending optimal path structures based on learning science?
• How do we measure and optimize for path completion rates?

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Learner Use Cases

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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.

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Casual Format Use Cases

7. Register Account

Actor: Learner

Main Success Scenario:

1. The learner navigates to the "Sign Up" page of the platform or app.
2. The learner selects the "Learner" role from account type options.
3. The learner provides required details:
   • Full name
   • Email address
   • Password (with confirmation)
   • Username
4. The learner can register using social media accounts (Google, Github, LinkedIn) as an alternative.
5. The learner agrees to Terms and Conditions and submits the form.
6. The system validates input (email format, password strength, username uniqueness).
7. The system sends a verification email to the provided address.
8. The learner clicks the OTP in the email.
9. The system activates the account and redirects to the login page.
10. 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."

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8. Login to System

Actor: Learner

Main Success Scenario:

1. The learner navigates to the login page in the platform or app.
2. The learner enters their email and password.
3. The learner can choose to log in using social media accounts (Google, Github, LinkedIn) as an alternative.
4. The learner clicks "Login."
5. The system validates credentials.
6. The system authenticates the learner and redirects to the dashboard.
7. 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."

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9. Recover Password

Actor: Learner

Main Success Scenario:

1. The learner clicks "Forgot Password" on the login page.
2. The learner enters their registered email address.
3. The system validates the email.
4. The system sends a password OTP to the email.
5. The learner enters the OTP received.
6. The learner enters and confirms a new password.
7. The system updates the password.
8. 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."

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10. Choose Learning Path

Actor: Learner

Main Success Scenario:

1. The learner logs into the platform or app.
2. The learner navigates to the "Learning Paths" section.
3. The system displays available tracks (Fundamentals, Machine Learning, Cybersecurity, Full-Stack Development).
4. The learner selects their preferred learning path.
5. The system shows a detailed overview including modules, estimated time, and prerequisites.
6. The learner confirms their selection by clicking "Start Path."
7. The system updates the learner's dashboard with the selected path.
8. 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."

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11. View Lesson Content

Actor: Learner

Main Success Scenario:

1. The learner navigates to their enrolled course from the dashboard.
2. The learner selects a module and clicks on a specific lesson.
3. The system displays the lesson content including:
   • Text explanation
   • Video tutorial
4. The learner reads/watches the content at their own pace.
5. The learner can pause, rewind, or fast-forward video content.
6. The system tracks time spent on the lesson.
7. The lesson is marked as complete when finished.
8. 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."

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12. Complete Exercise

Actor: Learner

Main Success Scenario:

1. The learner navigates to the exercises section of a lesson.
2. The learner selects an available coding challenge.
3. The system displays the problem statement, input/output examples, and starter code.
4. The learner writes code in the Code Editor in platform.
5. The learner drag/drop blocks of code in the blockly Editor in app.
6. The learner clicks "Run Tests" to validate their solution.
7. The system executes the code against test cases.
8. The system displays results showing passed/failed test cases.
9. If all tests pass, the learner clicks "Submit Solution."
10. The system awards XP and updates skill mastery.
11. 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."

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13. Track Progress and View Learning Analytics

Actor: Learner

Main Success Scenario:

1. The learner navigates to the "Progress & Analytics" section from the dashboard.
2. The system displays a comprehensive dashboard with two main views:
   • Progress Overview
   • Detailed Analytics
3. Progress Overview Section displays:
   • Completed modules and lessons
   • Current XP and level
   • Skill mastery percentages
   • Time spent learning
   • Streak information
4. Detailed Analytics Section displays:
   • Accuracy rates per skill
   • Time-to-completion trends
   • Learning velocity
   • Performance metrics with charts and graphs
5. The system highlights weak areas and recommends improvement exercises based on analytics.
6. The learner can view predictions and insights:
   • Estimated time to complete current path
   • Suggested focus areas
7. 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

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14. Earn XP and Level Up

Actor: Learner

Main Success Scenario:

1. The learner completes a lesson, exercise, or challenge.
2. The system calculates earned XP based on:
   • Task difficulty
   • Completion time
   • Accuracy
   • Streak bonuses
3. The system adds XP to the learner's total.
4. If the learner reaches a level threshold, the system triggers level-up animation.
5. The learner sees a congratulatory message with new level badge.
6. 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]."

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15. Set Language Preferences

Actor: Learner

Main Success Scenario:

1. The learner navigates to Settings.
2. The learner selects "Language Preferences."
3. The system displays options for:
   • Interface language (Arabic/English)
   • Primary programming language (Python/JavaScript) in platform.
4. The learner makes selections and clicks "Save."
5. The system updates preferences and refreshes the interface.
6. 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."

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16. Bookmark Lesson

Actor: Learner

Main Success Scenario:

1. The learner is viewing a lesson.
2. The learner clicks the "Bookmark" icon.
3. The system adds the lesson to the learner's bookmarks.
4. The learner sees confirmation: "Lesson bookmarked!"
5. 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."

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17 . Share Solution

Actor: Learner

Main Success Scenario:

1. The learner completes an exercise successfully.
2. The learner navigates to the "Solution Gallery" section.
3. The learner clicks "Share My Solution."
4. The learner adds optional comments or explanations.
5. The learner submits the solution for community viewing.
6. The system publishes the solution with the learner's profile.
7. 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.

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Fully Dressed Format Use Cases

18. Enable Two-Factor Authentication

Primary Actor: Learner

Stakeholders and Interests:

• 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:

1. The learner navigates to Account Settings.
2. The learner selects "Security" tab.
3. The learner clicks "Enable Two-Factor Authentication."
4. The system displays 2FA setup options:
   • Authenticator app (recommended)
   • Email verification code
5. The learner selects "Authenticator App."
6. The system generates a QR code and secret key.
7. The system displays instructions:
   • "Scan this QR code with your authenticator app (Google Authenticator, Authy, etc.)"
8. The learner opens their authenticator app and scans the QR code.
9. The authenticator app adds the DuoCode account and begins generating codes.
10. The system prompts: "Enter the 6-digit code from your authenticator app to confirm setup."
11. The learner enters the current code from their app.
12. The system validates the code.
13. The system generates 10 backup recovery codes.
14. The system displays the recovery codes with instructions:
    • "Save these codes securely. Each can be used once if you lose access to your authenticator."
15. The learner downloads or copies the recovery codes.
16. The learner confirms they've saved the codes by checking a box.
17. The system enables 2FA on the account.
18. The learner sees confirmation: "Two-Factor Authentication is now active. Your account is more secure!"
19. The system logs out all other sessions for security.
20. 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:
  • The system displays: "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:
  • The system displays: "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:
  • The system displays: "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

Stakeholders and Interests:

• 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:

1. The learner navigates to a coding exercise or lesson on the web platform.
2. The system loads the Code Editor with syntax highlighting for the selected language (Python/JavaScript).
3. 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
4. The learner writes their code in the Code Editor.
5. 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
6. The learner can customize editor settings:
   • Font size adjustment
   • Theme selection (dark/light mode)
   • Tab size configuration
   • Line numbers toggle
7. The learner clicks "Run Code" to test their solution.
8. The system sends the code to the secure execution API via HTTPS.
9. The execution API runs the code in an isolated Docker sandbox environment.
10. 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
11. The results are displayed in the output console below the editor with syntax highlighting.
12. The learner can view detailed execution metrics in an expandable panel.
13. If the output matches expected results, the learner clicks "Submit Solution."
14. The system validates the solution against all test cases (visible and hidden).
15. The system displays test results:
    • Passed test cases (✓ in green)
    • Failed test cases (✗ in red) with input/output comparison
    • Edge cases handled correctly
16. 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
17. 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:
  • The system displays in output console:

    ✗ 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:
  • The system terminates execution and displays:

    ⏱️ 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:
  • The system displays:

    💾 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:
  • The system displays detailed comparison:

    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:
  • The system displays:

    ⚠️ 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?

---

20. Practice Coding with Blockly Editor (Mobile App)

Primary Actor: Learner

Stakeholders and Interests:

• 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:

1. The learner navigates to a coding exercise on the mobile app.
2. The system detects the device type and loads the Blockly visual editor.
3. 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
4. The problem requires building a simple program (e.g., "Calculate sum of numbers in a list").
5. 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)
6. The learner selects a "create variable" block and names it sum.
7. The learner drags a "set variable to" block to the workspace.
8. The learner adds a "for each item in list" loop block.
9. Inside the loop, learner adds a "set sum to sum + item" block.
10. 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
11. 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
12. The system shows real-time validation:
    • Incomplete blocks highlighted in yellow
    • Required connections shown with puzzle piece icons
    • Error indicators if logic is invalid
13. The learner taps "Run Code" button.
14. The system converts blocks to executable code (Python or JavaScript):

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

15. The generated code is displayed in a collapsible "View Code" panel.
16. The learner can switch between:
    • Block View (visual programming)
    • Code View (text-based equivalent)
    • Split View (both simultaneously)
17. The system sends the generated code to the execution API.
18. The execution API runs the code in a secure sandbox.
19. The output console displays results:
    • Console output: 15
    • Execution time: 0.02s
    • Memory used: 12MB
20. If output is correct, the learner taps "Submit Solution."
21. 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 ✓
22. 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)
23. The learner sees a summary screen:
    • "🎉 Exercise Completed!"
    • XP earned: +30 XP
    • Total XP: 450 XP
    • Next exercise unlocked
24. The block program is saved to the learner's solution history.
25. 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:
  • System displays: "⚠️ 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:
  • System displays: "📡 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?

21. Receive AI-Powered Hints

Primary Actor: Learner

Stakeholders and Interests:

• 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:

1. The learner is working on a coding exercise and encounters difficulty.
2. The learner clicks the "Get Hint" button.
3. The system analyzes the learner's current code and attempt history.
4. The system determines the learner's skill level and hint count for this exercise.
5. The system sends a request to the AI API with:
   • Problem statement
   • Learner's current code
   • Skill level
   • Previous hint history
   • Requested hint level
6. The AI API processes the request and generates an appropriate hint.
7. The AI returns a hint that:
   • Doesn't reveal the complete solution
   • Addresses the learner's specific issue
   • Matches the learner's comprehension level
8. The system displays the hint in a panel below the editor.
9. The hint includes:
   • Conceptual guidance
   • Suggested approach
   • Relevant examples (if needed)
10. The learner reads the hint and applies the guidance.
11. The system tracks the hint usage and adjusts XP rewards accordingly.
12. 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:
  • The system displays: "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:
  • The system displays: "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:
  • The system displays: "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 system displays: "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:
  • The system doesn't send to AI and displays: "Please ensure your code is appropriate before requesting hints."

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?

---

22. Complete Certification Track

Primary Actor: Learner

Stakeholders and Interests:

• 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:

1. The learner is enrolled in a learning path (e.g., "Python Full-Stack Developer" from Use Case 10).
2. 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
3. The system tracks progress in the learner's dashboard:
   • Progress bar shows: 95% complete
   • Status: "Final Challenge Unlocked"
4. The learner navigates to the learning path dashboard.
5. The system displays: "🎉 You're almost there! Complete the final challenge to earn your certification."
6. The learner clicks "Start Final Challenge."
7. 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
8. The learner works on the final challenge project using skills learned throughout the path.
9. The learner tests their application thoroughly.
10. The learner clicks "Submit Final Challenge."
11. The system prompts for submission details:
    • GitHub repository URL
    • Live deployment URL
    • Project description (optional)
    • Technologies used
12. The learner provides all required information and clicks "Confirm Submission."
13. The system validates submission:
    • Checks if URLs are accessible
    • Verifies repository contains code
    • Scans for plagiarism using code similarity detection
14. 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)
15. 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
16. If the learner achieves 70+ points:
    • The system displays: "✅ Congratulations! Your project meets certification standards."
17. 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)
18. The system displays certificate preview with animation:
    • Confetti effect
    • Achievement sound
    • Certificate appears with fade-in animation
19. 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
20. The system sends congratulatory email with:
    • Certificate PDF attachment (high-resolution, printable)
    • Certificate verification link
    • Social sharing templates
    • LinkedIn credential integration link
21. The learner can now:
    • Download certificate as PDF
    • Share on social media (LinkedIn, Twitter, Facebook)
    • Add to digital portfolio
    • Print for display
22. 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"
23. The learning path is marked as "Completed" in learner's dashboard.
24. The system recommends next learning paths:
    • "Advanced Python Development"
    • "DevOps for Full-Stack Developers"
    • "React Native Mobile Development"
25. 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:
  • The system displays: "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:
  • The system displays: "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:
  • The system displays: "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:
  • The system displays: "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):
  • The system displays: "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:
  • The system displays: "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:
  • The system displays: "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?

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Primary Actor: Learner

Stakeholders and Interests:

• Learner: Wants to earn a credential that validates their programming skills.
• Platform: Needs to ensure certification standards are maintained and verifiable.
• Potential Employers/Institutions: Want assurance that certifications represent genuine competency.

Preconditions:

• Learner must be logged in.
• Learner must meet prerequisite requirements for the certification track.
• Certification must be available and active.
• Learner must have completed required foundational courses.

Postconditions:

• All certification requirements are completed.
• Learner receives a digital certificate.
• Certificate is added to learner's profile and can be shared.
• Certification data is recorded in the system.

Main Success Scenario:

1. The learner navigates to the "Certifications" section.
2. The system displays available certification tracks with details:
   • Required skills
   • Time commitment
   • Prerequisites
   • Benefits
3. The learner selects a certification track (e.g., "Python Programming Fundamentals").
4. The system verifies the learner meets prerequisites.
5. The learner clicks "Enroll in Certification."
6. The system creates a certification dashboard showing:
   • Required courses (5-10 courses)
   • Final assessment
   • Completion deadline (if applicable)
   • Progress tracker
7. The learner works through required courses and completes lessons/exercises.
8. The system tracks completion of each requirement.
9. The learner completes required portfolio projects:
   • Builds functional applications
   • Submits projects for review
   • Receives feedback and approval
10. After completing all courses and projects, the learner becomes eligible for the final assessment.
11. The learner starts the final certification exam:
    • Timed coding challenges (90-120 minutes)
    • Multiple difficulty levels
    • Real-world problem scenarios
12. The learner completes the exam within the time limit.
13. The system auto-grades objective questions and submits code for evaluation.
14. If code evaluation requires human review, the system assigns a mentor reviewer.
15. The reviewer evaluates code quality, efficiency, and correctness.
16. If the learner achieves the passing score (e.g., 70% or higher):
    • The system generates a digital certificate with unique ID.
    • Certificate includes: learner name, certification title, completion date, certificate ID, platform signature.
17. The system adds the certificate to the learner's profile.
18. The learner receives an email with certificate PDF and OTP.
19. The learner can share the certificate on LinkedIn, resume, or portfolio.
20. The certificate is permanently recorded on blockchain for verification (optional feature).

Alternative Scenarios:

A1. Prerequisites Not Met

• At Step 4, if prerequisites aren't completed:
  • The system displays: "You need to complete [Course Names] before enrolling in this certification."
  • The system shows a clear path to complete prerequisites.
  • The learner is offered to start the prerequisite courses.

A2. Enrollment Limit Reached

• At Step 5, if certification enrollment is at capacity:
  • The system displays: "This certification track is currently full. Join the waitlist to be notified when spots open."
  • The learner can join the waitlist.

A3. Project Submission Rejected

• At Step 9, if a project doesn't meet requirements:
  • The reviewer provides specific feedback on issues.
  • The system displays: "Your project needs revision. See reviewer comments for details."
  • The learner revises and resubmits (up to 2 additional attempts).
  • If third attempt fails, the learner must retake prerequisite materials.

A4. Failed Final Assessment

• At Step 16, if the score is below passing threshold:
  • The system displays: "You scored [X]%, but need 70% to pass. Review the areas where you struggled and try again."
  • The system identifies weak skills and recommends review materials.
  • The learner must wait 7 days before retaking.
  • The learner gets up to 3 attempts total.

A5. Time Limit Exceeded on Exam

• At Step 12, if the learner doesn't complete within time:
  • The system auto-submits completed portions.
  • Incomplete sections receive no credit.
  • The attempt counts toward the maximum allowed.

A6. Technical Issues During Exam

• At Step 11-12, if system issues occur:
  • The system saves all work automatically every 30 seconds.
  • If disconnected, the learner can resume with remaining time.
  • If issue is system-wide, the exam is rescheduled without penalty.

A7. Deadline Missed

• If certification has a deadline (e.g., 6 months):
  • 2 weeks before deadline: System sends reminder email.
  • 1 week before: System sends urgent notification.
  • If missed: "The deadline for this certification has passed. You can re-enroll for the next cohort."

A8. Plagiarism Detected

• At Step 9 or 13, if code plagiarism is detected:
  • The system flags the submission for admin review.
  • Admin investigates and may disqualify the learner.
  • Serious violations result in temporary suspension.

Extensions:

E1. Early Completion Bonus

• If the learner completes ahead of schedule:
  • The system awards a "Fast Learner" badge.
  • The certificate includes an "Accelerated Track" distinction.

E2. Certificate Verification

• Anyone can verify certificate authenticity:
  • Enter certificate ID on platform verification page.
  • System displays certificate details and learner name.
  • Blockchain verification ensures tampering prevention.

E3. Certificate Levels

• Certifications come in tiers:
  • Bronze: Basic proficiency (70-79%)
  • Silver: Solid competence (80-89%)
  • Gold: Excellence (90-100%)
• Certificate design reflects achievement level.

E4. Portfolio Showcase

• Completed certification projects are featured in learner's public portfolio.
• Projects can be viewed by recruiters or other learners.
• Code quality and creativity are highlighted.

E5. Certification Expiry and Renewal

• Some certifications require renewal every 2 years.
• System notifies learner 3 months before expiry.
• Renewal involves completing updated modules and a shorter assessment.

Special Requirements:

• Final assessments must be proctored using AI monitoring (webcam + screen recording) to prevent cheating.
• Certificates must include unique verification IDs.
• Certificate PDFs must be downloadable and professionally formatted.
• The system must track all certification attempts and scores.
• Mentor reviewers must complete evaluations within 5 business days.
• Certificates must comply with digital credential standards.
• All exam content must be kept confidential and rotated regularly.

Frequency of Use:

• Lower frequency compared to regular learning activities.
• Estimated 20-30% of active learners pursue certifications.
• Peak enrollment periods: End of quarter/year.

Open Issues:

• Should certifications have an expiration date?
• How do we price premium certifications vs. free learning?
• Should we partner with universities for credit recognition?
• What level of anti-cheating measures is appropriate?

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