Heuristic Evaluation Skill

Heuristic Evaluation

Systematic usability review using established principles.

When to Trigger

User shares a screenshot, mockup, or prototype
User asks for design feedback or review
User asks "what's wrong with this"
User wants to improve an interface
Before shipping user-facing changes

Quick Start

Ask user to share the interface (screenshot, URL, or description)
Ask: "Any specific flows or areas of concern?"
Run evaluation using Nielsen's 10 (default) or requested framework

Core Workflow

Heuristic Evaluation Progress:
- [ ] Step 1: Capture interface context
- [ ] Step 2: Select evaluation framework
- [ ] Step 3: Evaluate against each heuristic
- [ ] Step 4: Score severity of issues
- [ ] Step 5: Prioritize recommendations

Step 1: Capture Context

Before evaluating, understand:

What is this? (App type, purpose)
Who uses it? (Target users, expertise level)
What task? (Primary user flow being evaluated)

If not provided, ask: "What are users trying to accomplish here?"

Step 2: Select Framework

Default: Nielsen's 10 Usability Heuristics

Alternatives (if user requests or context suggests):

Shneiderman's 8 Golden Rules — for interaction-heavy interfaces
Cognitive Walkthrough — for first-time user experience
Custom rubric — if user provides one

See references/frameworks.md for full framework details.

Step 3: Nielsen's 10 Evaluation

For each heuristic, identify violations:

| # | Heuristic | What to look for | |---|-----------|------------------| | 1 | Visibility of system status | Loading indicators, progress, confirmation, current state | | 2 | Match real world | Familiar language, logical order, conventions from domain | | 3 | User control & freedom | Undo, cancel, exit, back navigation, escape hatches | | 4 | Consistency & standards | Same words/actions mean same things, platform conventions | | 5 | Error prevention | Confirmations for destructive actions, constraints, defaults | | 6 | Recognition over recall | Visible options, contextual help, no memorization required | | 7 | Flexibility & efficiency | Shortcuts, customization, accelerators for experts | | 8 | Aesthetic & minimalist | No irrelevant info, clear hierarchy, signal vs noise | | 9 | Help users with errors | Plain language errors, specific problem, constructive solution | | 10 | Help & documentation | Searchable, task-focused, concise, accessible when needed |

Step 4: Score Severity

Rate each issue found:

| Score | Severity | Description | |-------|----------|-------------| | 0 | Not a problem | Disagreement with heuristic but not usability issue | | 1 | Cosmetic | Fix only if time permits | | 2 | Minor | Low priority, causes minor friction | | 3 | Major | High priority, significant impact on task completion | | 4 | Catastrophic | Must fix before release, prevents task completion |

Scoring factors:

Frequency: How often does user encounter this?
Impact: How much does it block the task?
Persistence: Can users work around it?

Step 5: Prioritize Output

Rank issues by: Severity × Frequency

Group into:

Fix immediately (Severity 4, or Severity 3 + high frequency)
Fix soon (Severity 3, or Severity 2 + high frequency)
Fix later (Severity 1-2, low frequency)

Output Template

Automatically save the output to design/08-heuristic-evaluation.md using the Write tool while presenting it to the user.

## Heuristic Evaluation: [Interface Name]

**Evaluated**: [Date]
**Framework**: Nielsen's 10 Usability Heuristics
**Scope**: [Specific flow or screens evaluated]

### Summary
- Critical issues: [count]
- Major issues: [count]  
- Minor issues: [count]

### Critical Issues (Fix Immediately)

#### Issue 1: [Brief description]
- **Heuristic violated**: #[number] — [name]
- **Location**: [Where in the interface]
- **Problem**: [What's wrong]
- **Impact**: [How it affects users]
- **Recommendation**: [How to fix]
- **Severity**: [0-4]

[Repeat for each critical issue]

### Major Issues (Fix Soon)
[Same format]

### Minor Issues (Fix Later)
[Same format, can be condensed to a table]

### Strengths Observed
- [What the interface does well]

### Next Steps
1. [Prioritized action]
2. [Prioritized action]

Adaptive Behavior

If user provides a screenshot:

Analyze visually
Call out specific elements by location
Be concrete: "The save button in the top right..." not "buttons should..."

If user describes interface:

Ask clarifying questions before evaluating
Focus on described pain points first

If user is designer:

Skip heuristic definitions
Use shorthand: "H4 violation" instead of explaining consistency

If user is developer:

Include implementation-aware suggestions
Note which fixes are quick wins vs architectural changes

Handoff

After presenting the evaluation, suggest:

"Use this report to prioritize fixes. Want me to help refine any screens based on these findings?"

Note: File is automatically saved to design/08-heuristic-evaluation.md for reference.

Integration Points

Works well with:

assumption-mapping — before building, question if the design addresses real needs
critique — for broader feedback beyond usability
accessibility-audit — for WCAG-specific evaluation

References

references/frameworks.md — Full heuristic definitions and alternatives
references/examples.md — Sample evaluations

Agent Skills: Heuristic Evaluation

Install this agent skill to your local

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