heuristic-evaluation
The heuristic-evaluation skill conducts systematic usability assessments of digital interfaces using Nielsen's ten established heuristics as a framework. Use this skill when reviewing interface designs before user testing to identify usability problems, document issues with severity ratings from zero to four, and generate prioritized recommendations for improvement across consistency, error prevention, user control, and other core usability dimensions.
git clone --depth 1 https://github.com/Owl-Listener/designer-skills /tmp/heuristic-evaluation && cp -r /tmp/heuristic-evaluation/prototyping-testing/skills/heuristic-evaluation ~/.claude/skills/heuristic-evaluationSKILL.md
# Heuristic Evaluation You are an expert in conducting systematic heuristic evaluations of digital interfaces. ## What You Do You evaluate interfaces against established usability heuristics to identify problems before user testing. ## Nielsen's 10 Usability Heuristics 1. **Visibility of system status** — Users know what is happening 2. **Match real world** — System speaks users' language 3. **User control and freedom** — Easy undo and exit 4. **Consistency and standards** — Follow conventions 5. **Error prevention** — Prevent problems before they occur 6. **Recognition over recall** — Make options visible 7. **Flexibility and efficiency** — Shortcuts for experts 8. **Aesthetic and minimalist design** — No irrelevant information 9. **Error recovery** — Help users recognize and recover from errors 10. **Help and documentation** — Provide assistance when needed ## Evaluation Process 1. Define scope (which screens/flows to evaluate) 2. Walk through as a new user 3. Walk through as an experienced user 4. Walk through each task flow 5. Document each issue found 6. Rate severity 7. Compile and prioritize findings ## Issue Documentation For each issue: heuristic violated, description, location, severity (0-4), screenshot/reference, recommendation. ## Severity Scale - 0: Not a usability problem - 1: Cosmetic only - 2: Minor problem - 3: Major problem (important to fix) - 4: Catastrophe (must fix before release) ## Best Practices - Multiple evaluators find more issues (3-5 ideal) - Evaluate independently before comparing - Focus on real user tasks, not edge cases - Don't just find problems — suggest solutions - Combine with real user testing for complete picture
Design an A/B experiment — hypothesis, variants, primary metric, and sample size. Use when a change can be measured quantitatively at scale. For observing behaviour qualitatively, use `test-scenario`.
Audit an existing interface against WCAG, producing findings with severity ratings and remediation steps. Use when you have a design or build to assess now. Not for planning future sessions with assistive-technology users — use `accessibility-test-plan` (prototyping-testing).
Plan accessibility testing — assistive technologies, participant criteria, WCAG coverage, and session protocol. Use when scheduling testing with real AT users. Not for evaluating a design yourself — use `accessibility-audit` (design-systems).
Apply the Aesthetic-Usability Effect — polished, consistent interfaces are perceived as more usable and forgive minor friction. Use when justifying visual polish or diagnosing why a functional design tests badly. For emotional resonance specifically, use `interfaces-that-feel` (interaction-design).
Cluster many qualitative data points into themes and insight statements. Use when synthesising across multiple sessions or sources. For a single transcript use `summarize-interview`; for one segment's inner state use `empathy-map`.
Apply animation principles — easing, staging, follow-through — to one specific UI motion. Use when tuning how an animation feels. For product-wide duration and easing tokens use `motion-system` (design-systems); for a full interaction spec use `micro-interaction-spec`.
A practitioner's toolkit for thinking and communicating as a designer in a business context — reading financials, mapping competitive landscapes, and defending design decisions in the language of value.
Analyse open or closed card sort results into a proposed grouping and label set. Use after running a sort study. For turning that evidence into a full structure, use `information-architecture` (ux-strategy).