Practical usability principles for evaluating and improving user interfaces. Based on a fundamental truth: users don't read, they scan. They don't make optimal choices, they satisfice. They don't figure out how things work, they muddle through.

Core Philosophy

"Don't Make Me Think" - Every page should be self-evident. If something requires thinking, it's a usability problem.

Krug's Three Laws of Usability

1. Don't Make Me Think

Every question mark that pops into a user's head adds to their cognitive load and distracts from the task.

Things that make users think:

Clever names vs. clear names
Marketing-speak vs. plain language
Unfamiliar categories or labels
Links that could go anywhere
Buttons with ambiguous labels

Self-evident vs. self-explanatory:

| "Get directions" | "Calculate route to destination"

| "Sign in" | "Access your account portal"

| "Add to cart" | "Proceed to purchase selection"

Goal: Self-evident. If that's impossible, self-explanatory.

2. It Doesn't Matter How Many Clicks

The myth: "Users will leave if it takes more than 3 clicks."

Reality: Users don't mind clicks if each click is:

Painless (fast, easy)
Obvious (no thinking required)
Confidence-building (they know they're on the right path)

Three mindless clicks > one confusing click

3. Get Rid of Half the Words, Then Half of What's Left

Benefits of brevity:

Reduces noise
Makes useful content more prominent
Makes pages shorter (less scrolling)
Shows respect for user's time

What to cut:

Happy-talk ("Welcome to our website!")
Instructions that nobody reads
"Please" and "Kindly" and polite fluff
Redundant explanations

The Trunk Test

A test for navigation clarity: can users answer these questions on any page?

| What site is this? | Brand/logo visible

| What page am I on? | Page title/heading clear

| What are the major sections? | Navigation visible

| What are my options at this level? | Links/buttons clear

| Where am I in the scheme of things? | Breadcrumbs/hierarchy

| How can I search? | Search box findable

If users can't answer these instantly, navigation needs work.

Nielsen's 10 Usability Heuristics

See: references/nielsen-heuristics.md for detailed explanations with examples.

Quick Reference

| 1 | Visibility of system status | Always show what's happening

| 2 | Match between system and real world | Use user's language, not yours

| 3 | User control and freedom | Easy undo and exit

| 4 | Consistency and standards | Same words, same actions

| 5 | Error prevention | Better than error messages

| 6 | Recognition rather than recall | Show options, don't require memory

| 7 | Flexibility and efficiency | Shortcuts for experts

| 8 | Aesthetic and minimalist design | Remove everything unnecessary

| 9 | Help users recognize, diagnose, recover from errors | Plain-language errors with solutions

| 10 | Help and documentation | Searchable, task-focused, concise

Heuristic Conflicts

Heuristics sometimes contradict each other. When they do:

Simplicity vs. Flexibility: Use progressive disclosure
Consistency vs. Context: Consistent patterns, contextual prominence
Efficiency vs. Error Prevention: Prefer undo over confirmation dialogs
Discoverability vs. Minimalism: Primary actions visible, secondary hidden

See heuristic-conflicts.md for resolution frameworks.

Dark Patterns Recognition

Dark patterns violate heuristics deliberately to manipulate users:

Forced continuity (hard to cancel)
Roach motel (easy in, hard out)
Confirmshaming (guilt-based options)
Hidden costs (surprise fees at checkout)

See dark-patterns.md for complete taxonomy and ethical alternatives.

Severity Rating Scale

When auditing interfaces, rate each issue:

| 0 | Not a problem | Disagreement, not usability issue | Ignore

| 1 | Cosmetic | Minor annoyance, low impact | Fix if time

| 2 | Minor | Causes delay or frustration | Schedule fix

| 3 | Major | Significant task failure | Fix soon

| 4 | Catastrophic | Prevents task completion | Fix immediately

Rating Factors

Consider all three:

Frequency: How often does it occur?
Impact: How severe when it occurs?
Persistence: One-time or ongoing problem?

Common Usability Violations

See: references/krug-principles.md for full Krug methodology.

| Mystery meat navigation | Icons without labels | Add text labels

| Too many choices | Decision paralysis | Reduce to 7±2 items

| Inconsistent nav location | Users can't find it | Fixed position always

| No "you are here" indicator | Lost users | Highlight current section

| Broken back button | Frustration | Never break browser history

Forms

| No inline validation | Submit → error → scroll | Validate on blur

| Unclear required fields | Confusion | Mark optional, not required

| Poor error messages | "Invalid input" | Explain what's wrong + how to fix

| Too many fields | Abandonment | Remove unnecessary fields

| Unexpected format requirements | Frustration | Accept all formats, normalize

Content

| Wall of text | Nobody reads | Break up, add headings

| Jargon | Confusion | Plain language

| Missing labels | Ambiguity | Label all inputs and sections

| Low contrast text | Unreadable | WCAG AA minimum (4.5:1)

| Important info below fold | Missed | Move up or add anchor

Interactions

| No loading indicators | "Is it broken?" | Show progress/spinner

| No confirmation on delete | Accidental loss | Confirm destructive actions

| Tiny tap targets | Mobile frustration | Minimum 44×44 px

| Hover-only info | Mobile users miss it | Don't hide critical info

| No undo | Fear of acting | Provide undo for all actions

Quick Audit Checklist

See: references/audit-template.md for full structured template.

5-Minute Scan

| Can I tell what site/page this is immediately? | [ ]

| Is the main action obvious? | [ ]

| Is the navigation clear? | [ ]

| Can I find the search? | [ ]

| Are there any dead ends? | [ ]

| Does anything make me think "huh?" | [ ]

15-Minute Audit

Run through Nielsen's 10 heuristics, rating each 0-4.

User Observation (Gold Standard)

Watch 3-5 users attempt key tasks:

Where do they hesitate?
Where do they click wrong?
What do they say out loud?
Where do they give up?

When to Use Each Method

| Heuristic evaluation | Before user testing | 1-2 hours | Major violations

| User testing | After heuristic fixes | 2-4 hours | Real behavior

| A/B testing | When optimizing | Days-weeks | Statistical validation

| Analytics review | Ongoing | 30 min | Patterns and problems

Common Excuses (And Reality)

| "Users will figure it out" | They won't. They'll leave.

| "We need to show everything" | Prioritize. Hide complexity.

| "It tested well with the team" | Team knows too much. Test with real users.

| "Adding help text will fix it" | Nobody reads help text. Simplify the UI.

| "Power users need all these options" | 95% of users never need them. Progressive disclosure.

| "It's industry standard" | Bad standards are still bad.

Reference Files

krug-principles.md: Full Krug methodology, scanning behavior, navigation clarity
nielsen-heuristics.md: Detailed heuristic explanations with examples
audit-template.md: Structured heuristic evaluation template
dark-patterns.md: Categories, examples, ethical alternatives, regulations
wcag-checklist.md: Complete WCAG 2.1 AA checklist, testing tools
cultural-ux.md: RTL, color meanings, form conventions, localization
heuristic-conflicts.md: When heuristics contradict, resolution frameworks

ux-heuristics

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