/product-ux-expert

name: product-ux-expert
description: Product interaction and UX expert. Use when reviewing UI/UX, conducting heuristic evaluations, designing user journeys, applying cognitive psychology principles, or ensuring WCAG 2.2 accessibility compliance.

Product UX Expert

Core Principles

• **Reduce Cognitive Load** — Minimize mental effort required for every interaction
• **Accessibility First** — WCAG 2.2 AA is the baseline, not an afterthought
• **Evidence-Based** — Decisions backed by user research, not assumptions
• **Anticipatory Design** — Predict user needs before they ask
• **Ethical Design** — No dark patterns, transparent data practices
• **Mobile First** — Design for smallest screens, enhance for larger

---

Quick Reference

Nielsen's 10 Heuristics

| # | Heuristic | Key Question | |---|-----------|--------------| | 1 | Visibility of System Status | Does the user always know what's happening? | | 2 | Match System & Real World | Does it use familiar language and concepts? | | 3 | User Control & Freedom | Can users easily undo or exit? | | 4 | Consistency & Standards | Does it follow platform conventions? | | 5 | Error Prevention | Does it prevent errors before they occur? | | 6 | Recognition over Recall | Is information visible, not memorized? | | 7 | Flexibility & Efficiency | Are there shortcuts for experts? | | 8 | Aesthetic & Minimalist Design | Is every element necessary? | | 9 | Help Users with Errors | Are error messages helpful and actionable? | | 10 | Help & Documentation | Is help available when needed? |

---

Cognitive Psychology

Cognitive Load Types

Intrinsic Load     — Complexity inherent to the task itself
Extraneous Load    — Unnecessary complexity from poor design (eliminate this!)
Germane Load       — Mental effort for learning/understanding (support this)

Key Laws

Hick's Law         — More choices = longer decision time
                   → Limit options to 5-7, use progressive disclosure

Miller's Law       — Working memory holds 7±2 items
                   → Chunk information, use visual grouping

Fitts's Law        — Larger, closer targets are easier to click
                   → Make primary actions big and accessible

Jakob's Law        — Users expect your site to work like others
                   → Follow established patterns

Von Restorff       — Different items are more memorable
                   → Highlight CTAs with contrast

Serial Position    — First and last items remembered best
                   → Put key info at start/end of lists

Gestalt Principles

Proximity          — Close elements are perceived as groups
Similarity         — Similar elements are perceived as related
Continuity         — Eyes follow smooth lines and curves
Closure            — Mind completes incomplete shapes
Figure-Ground      — Elements seen as foreground or background
Common Region      — Elements in same area are grouped

---

Heuristic Evaluation

Process

1. Define scope         — What screens/flows to evaluate
2. Select evaluators    — 3-5 UX experts (80%+ issues found)
3. Independent review   — Each expert reviews alone
4. Apply heuristics     — Rate severity for each issue
5. Consolidate          — Merge findings, remove duplicates
6. Prioritize           — Rank by severity × frequency
7. Report               — Actionable recommendations

Severity Rating

| Level | Severity | Description | |-------|----------|-------------| | 0 | Not a problem | Evaluator disagrees it's an issue | | 1 | Cosmetic | Fix only if extra time available | | 2 | Minor | Low priority, causes friction | | 3 | Major | High priority, significant impact | | 4 | Catastrophic | Must fix before release |

Issue Template

## Issue: [Brief Description]

**Heuristic:** #N - Name
**Severity:** 0-4
**Location:** Screen / Component / Flow

**Problem:**
What's wrong and why it matters to users.

**Evidence:**
Screenshot or recording link.

**Recommendation:**
Specific fix with before/after comparison.

---

User Journey Mapping

Journey Map Structure

┌─────────────────────────────────────────────────────────────────┐
│  PERSONA: [Name, Goals, Context]                                │
├─────────┬─────────┬─────────┬─────────┬─────────┬──────────────┤
│ Stage   │ Aware   │ Consider│ Purchase│ Use     │ Advocate     │
├─────────┼─────────┼─────────┼─────────┼─────────┼──────────────┤
│ Actions │ Search  │ Compare │ Signup  │ Onboard │ Share/Review │
├─────────┼─────────┼─────────┼─────────┼─────────┼──────────────┤
│ Touch-  │ Search  │ Website │ Checkout│ App     │ Social       │
│ points  │ Ads     │ Reviews │ Email   │ Support │ Email        │
├─────────┼─────────┼─────────┼─────────┼─────────┼──────────────┤
│ Emotions│   😐    │   🤔    │   😟    │   😊    │    😍        │
│         │ curious │ hopeful │ anxious │ relieved│  delighted   │
├─────────┼─────────┼─────────┼─────────┼─────────┼──────────────┤
│ Pain    │ Too many│ Info    │ Complex │ Unclear │ No referral  │
│ Points  │ options │ overload│ forms   │ next    │ program      │
├─────────┼─────────┼─────────┼─────────┼─────────┼──────────────┤
│ Opportu-│ Clear   │ Compare │ 1-click │ Progress│ Share        │
│ nities  │ tagline │ table   │ signup  │ tracker │ incentive    │
└─────────┴─────────┴─────────┴─────────┴─────────┴──────────────┘

Touchpoint Analysis

For each touchpoint, evaluate:

1. Entry Point      — How do users arrive?
2. User Goal        — What are they trying to accomplish?
3. Friction         — What slows them down?
4. Emotion          — How do they feel?
5. Drop-off Risk    — Where might they abandon?
6. Opportunity      — How can we improve?

---

Accessibility (WCAG 2.2 AA)

POUR Principles

Perceivable     — Can users perceive the content?
                  ✓ Text alternatives for images
                  ✓ Captions for video
                  ✓ 4.5:1 color contrast