Product Evaluation Skill
Evaluate the product from a real user's perspective. Produce a numerical score across 4 dimensions (total /100). Threshold to pass: 70/100.
Prerequisites
- If
ux-audithas already been run for this PR, use its results (screenshots, performance metrics, interaction findings) as input. Do NOT re-run the same checks — build on what ux-audit already verified. - Start the dev server or confirm the deployed app URL is accessible.
- Use Playwright MCP to navigate, interact, and screenshot every screen evaluated.
- Adopt the target user's persona — their technical level, goals, context. Do NOT evaluate as a developer.
Phase 0: User Research (before scoring)
Conduct user research BEFORE scoring dimensions. Real user data prevents you from evaluating in a vacuum.
The Mom Test (Rob Fitzpatrick)
Never ask "Would you use this?" or "Do you think this is a good idea?" — people lie to be polite. Instead, ask about their life, their problems, their current behavior. Talk about specifics in the past, not hypotheticals about the future. Talk less, listen more.
5 Interview Questions That Work
- "What's the hardest part about [task this product solves]?"
- "Tell me about the last time that happened — walk me through it"
- "What have you tried so far to solve it?"
- "What don't you love about [their current solution]?"
- "If you had a magic wand, what would it do?"
Avoid: generic claims ("I usually..."), future promises ("I would..."), and hypothetical maybes ("I might..."). These are worthless signals.
Guerrilla Usability Testing
Give 3-5 users a specific task (e.g., "sign up and create your first project"). Watch silently — do not help. Note where they hesitate, click wrong things, or ask questions. Each confusion point = a usability issue. Sessions should be under 15 minutes. You only need 3-5 participants to surface the most critical problems.
When to Run User Research
- Before product-eval scoring — use findings to inform dimension scores
- After major feature releases — validate that the feature solves the intended problem
- When churn spikes — exit interviews reveal why users leave
Store all findings in auto memory (memory/user_research.md) with: date, participant count, method (interview/usability test), and top 3 findings.
Dimension 1: Usability (30 points) — Nielsen's 10 Heuristics
Source: Jakob Nielsen, "10 Usability Heuristics for User Interface Design" (1994, updated 2020).
For each heuristic, navigate the app, check for violations, and rate severity on Nielsen's 0-4 scale:
- 0 = not a problem, 1 = cosmetic, 2 = minor, 3 = major, 4 = catastrophe
| # | Heuristic | What to check |
|---|---|---|
| 1 | Visibility of system status | Loading indicators, progress bars, state feedback |
| 2 | Match between system and real world | Jargon-free labels, familiar icons, logical ordering |
| 3 | User control and freedom | Undo/redo, cancel, back navigation, exit points |
| 4 | Consistency and standards | Same action = same result everywhere, platform conventions |
| 5 | Error prevention | Confirmations on destructive actions, input constraints, defaults |
| 6 | Recognition rather than recall | Visible options, contextual info, no memorization required |
| 7 | Flexibility and efficiency of use | Shortcuts for experts, customizable workflows |
| 8 | Aesthetic and minimalist design | No irrelevant info, clear visual hierarchy, whitespace |
| 9 | Help users recognize, diagnose, recover from errors | Plain-language errors, specific cause, constructive suggestion |
| 10 | Help and documentation | Searchable, task-oriented, concise, accessible when needed |
Score: 30 minus the sum of all severity ratings. If any single heuristic scores severity 4 (catastrophe), the entire dimension scores 0/30 regardless of the sum.
Dimension 2: Learnability (25 points) — Cognitive Walkthrough
Source: Wharton, Rieman, Lewis & Polson, "The Cognitive Walkthrough Method" (1994).
- Pick 3-5 critical user tasks (the tasks a new user must complete to get value).
- For each task, list every discrete step a novice user must take.
- At each step, answer these 4 questions:
- Q1: Will the user try to achieve the right effect?
- Q2: Will the user notice the correct action is available?
- Q3: Will the user associate the correct action with the desired effect?
- Q4: Will the user see that progress is being made toward their goal?
- A step passes only if all 4 answers are Yes.
Score: (passing steps / total steps) x 25. Target: 80%+ steps pass.
Dimension 3: First-Time Experience (25 points) — FTUE Audit
Evaluate as a brand-new user arriving with zero context.
| Criteria | Scoring |
|---|---|
| Time-to-Value — how long until the user gets real value | <=2 min: 10 pts, <=5 min: 7 pts, >5 min: 3 pts |
| Value proposition clarity — does the user immediately understand what this does and why it matters | Immediately obvious: 5 pts, Requires reading: 3 pts, Unclear: 0 pts |
| Steps to first success — count clicks/inputs to complete the primary task once | <=3 steps: 5 pts, 4-6 steps: 3 pts, >6 steps: 1 pt |
| Onboarding quality — how is the user guided through their first experience | Contextual guidance: 5 pts, Generic walkthrough: 3 pts, None: 0 pts |
Score: Sum of all four criteria (max 25).
Dimension 4: Engagement Signals (20 points) — Google HEART Framework
Source: Google HEART framework (Rodden, Hutchinson & Fu, 2010). This is a design-time assessment, not analytics-based.
Rate each signal 1-5 based on what you observe in the product:
- Happiness (1-5): Would a user feel satisfied after using this? Would they recommend it?
- Engagement (1-5): Is there a reason to come back? Is the core loop compelling?
- Adoption (1-5): Would new users complete onboarding? Is the barrier low enough?
- Retention (1-5): What would bring users back tomorrow? Next week? Is there a hook?
- Task Success (1-5): Can users complete their primary task without frustration or confusion?
Score: (sum of all 5 ratings / 25) x 20. Max 20 points.
Scoring and Grading
Total: Usability + Learnability + FTUE + Engagement = X / 100
| Score | Grade | Action |
|---|---|---|
| 90-100 | A | Ship with confidence |
| 80-89 | B | Ship, minor polish recommended |
| 70-79 | C | Ship with known issues documented |
| 60-69 | D | Do NOT ship — fix priority issues first |
| < 60 | F | Major rework needed — re-run iteration protocol below after fixes |
Pass threshold: 70/100. Below 70 → enter the Iteration Protocol below.
Output Format
## Product Evaluation Report
Dimension 1: Usability — X/30
[list each violated heuristic with severity rating and evidence]
Dimension 2: Learnability — X/25
[list each task, steps, and which steps failed with reason]
Dimension 3: First-Time Experience — X/25
[time-to-value measurement, steps to first success count, onboarding assessment]
Dimension 4: Engagement Signals — X/20
[each HEART signal with rating and justification]
TOTAL: X/100 (Grade: X)
Priority issues: [top 3 by severity — what to fix first]
After Scoring
Store the evaluation result in auto memory (memory/product_scores.md) with: timestamp, total score, per-dimension scores, grade, and the top 3 priority issues.
Iteration Protocol (if score < 70)
When the score is below 70, enter this auto-fix loop. Max 3 rounds.
Each Round:
PRIORITIZE — Take top 3 issues by severity from the evaluation report. For each: concrete action, files to touch, expected score impact.
FIX — One issue at a time:
- Write/edit the code
- Invoke
self-reviewon changed files - Run
test-gateto verify no regression - If tests fail → revert immediately, move to next issue
- Commit via
pre-commit— one atomic commit per fix
RE-EVALUATE — Re-run the 4 dimensions above on the updated product. Compare: new score vs previous. Log delta per dimension.
LEARN — Store in auto memory (
memory/product_scores.md): issue fixed, change made, score impact (e.g., "+5 on FTUE"). Builds a reusable knowledge base of high-impact improvements.CHECK — Score ≥ 70 → exit. Score < 70 AND round < 3 → continue. Round = 3 → exit with remaining issues listed.
Exit Report
## Iteration Summary
Rounds completed: N
Starting score: X/100 → Final score: Y/100
Improvements made:
1. [issue] → [fix] → [score impact]
Remaining issues (if still < 70):
1. [issue] — reason not fixed
Safety Rules
- Max 3 rounds — hard cap, prevents infinite loops
- Self-review every fix — no quality shortcuts under automation
- Revert on test failure — undo immediately if anything breaks
- Stop on user-input issues — business decisions, missing credentials require human input
Next Steps
Report to user: "Product score: [N]/100. Grade: [letter]. Top issues: [list]"
Suggested next steps (user decides):
- Score ≥ 70 → "Run copy-craft for launch page"
- Score < 70 → "Fix top issues, then re-evaluate"
- Ready to announce → "Run content-create"