UX Evaluator

Overview

Systematically evaluate UI components against established UX principles using a 3-dimension framework. Transform subjective design feedback into actionable, evidence-based recommendations by comparing against industry conventions and authoritative sources.

Core Value: Prevents subjective design debates by grounding decisions in documented best practices.

When to Use This Skill

Triggers:

• User provides UX feedback on a component
• User references external design guidelines (Balsamiq, Nielsen, Material Design)
• User asks to "review", "evaluate", or "check" UI elements
• User questions button labels, spacing, or visual hierarchy
• Before implementing UI changes that affect user interaction

Do NOT use for:

• Pure visual aesthetics (colors, fonts) without UX implications
• Backend or non-UI changes
• When user has already made a firm decision and just wants implementation

Evaluation Framework

The 3-Dimension Analysis

For ANY UI component, evaluate these three dimensions:

Dimension	What to Analyze	Key Questions
1. Position	Where is it located relative to other elements?	Does position follow conventions? Is it discoverable?
2. Visual Weight	How prominent is it visually?	Does it compete with primary actions? Is hierarchy clear?
3. Spacing	What's the gap from adjacent elements?	Is there adequate separation? Is spacing consistent?

Evaluation Workflow

Step 1: GATHER CONTEXT
├── What component is being evaluated?
├── What user feedback or concern triggered this?
├── Is there an external reference (article, guideline)?
└── What is the component's purpose (primary CTA, utility, navigation)?

Step 2: ANALYZE CURRENT STATE
├── Position: Document exact location in layout
├── Visual Weight: Describe styling (filled, ghost, icon-only, etc.)
├── Spacing: Measure gaps from adjacent elements
└── Compare to industry conventions (see references/)

Step 3: PRODUCE VERDICT
├── For each dimension: CORRECT / NEEDS CHANGE / ACCEPTABLE
├── If NEEDS CHANGE: Specific recommendation with rationale
├── Reference authoritative source for each recommendation
└── Prioritize changes (P1: breaks UX, P2: suboptimal, P3: polish)

Component-Specific Guidelines

Buttons (Action Elements)

Position:

• Primary action (Sign Up, Submit, Buy) → RIGHT side
• Secondary action (Cancel, Sign In) → LEFT of primary
• Utility controls (theme, settings) → FAR RIGHT after primary actions

Visual Weight:

• Primary: Filled background, brand color, shadow
• Secondary: Ghost/outline, no fill, subtle border
• Utility: Icon-only or minimal text, neutral color

Spacing:

• Between button groups: 1.5rem (24px) minimum
• Between buttons in same group: 0.5rem-0.75rem (8-12px)
• Touch targets: 44px minimum height on mobile

Labels:

• Use conventional labels: "Sign Up" not "Get Started", "Sign In" not "Login"
• Say exactly what happens: "Delete Account" not "Proceed"
• Verb-first for actions: "Create Project", "Send Message"

Navigation Elements

Position:

• Logo → LEFT
• Primary nav → CENTER or after logo
• Utility items (search, auth, theme) → RIGHT

Visual Weight:

• Active state clearly distinguished
• Current page indicator visible
• Don't compete with page content

Spacing:

• Group related items visually
• Clear separation between nav groups
• Adequate click/tap targets

Form Elements

Position:

• Labels above or to the left of inputs
• Submit button at bottom, right-aligned or full-width
• Error messages adjacent to field

Visual Weight:

• Required fields marked clearly
• Error states prominent (red border/text)
• Success states confirmatory (green checkmark)

Spacing:

• Consistent vertical rhythm between fields
• Label-to-input gap: 0.25-0.5rem
• Field-to-field gap: 1-1.5rem

Industry Conventions Reference

Button Order (Major Sites)

Site	Pattern
GitHub	[Sign In] [Sign Up] - secondary left, primary right
Stripe	[Sign In] [Start now →] - secondary left, primary right
Google	[Sign In] [Create account] - same pattern
Notion	[Log in] [Get Notion free] - same pattern

Verdict: Secondary LEFT, Primary RIGHT is the standard.

Theme Toggle Placement

Site	Placement
GitHub	Far right, after user menu
VS Code Docs	Far right
Stripe Docs	Far right
Discord	In settings, not navbar

Verdict: Far right (after auth) or in settings dropdown.

Utility Control Visual Weight

Control	Expected Weight
Theme toggle	Icon-only, subtle, doesn't compete with CTAs
Search	Icon trigger or compact input, expandable
Language selector	Icon or compact dropdown

Verdict: Utilities should be accessible but subordinate to primary actions.

Output Format

When evaluating a component, produce this structured output:

## [Component Name] Evaluation

### Current State
- **Position**: [Description]
- **Visual Weight**: [Description]
- **Spacing**: [Measurements]

### Analysis

| Dimension | Assessment | Rationale |
|-----------|------------|-----------|
| Position | [OK/CHANGE] | [Why, with reference] |
| Visual Weight | [OK/CHANGE] | [Why, with reference] |
| Spacing | [OK/CHANGE] | [Why, with reference] |

### Verdict: [CORRECT / NEEDS CHANGES]

### Recommendations (if any)
| Priority | Change | Rationale |
|----------|--------|-----------|
| P1 | [Specific change] | [Reference to principle] |
| P2 | [Specific change] | [Reference to principle] |

References

See references/ for detailed UX principles:

• balsamiq-button-principles.md - Button design best practices
• nielsen-heuristics.md - 10 usability heuristics (to be added)

Self-Monitoring

Before finalizing evaluation:

• All 3 dimensions analyzed (Position, Visual Weight, Spacing)
• Current state documented with specifics (not vague descriptions)
• Each recommendation references an authoritative source or convention
• Compared against industry conventions (GitHub, Stripe, etc.)
• Priorities assigned (P1/P2/P3) based on UX impact
• Verdict is clear and actionable