Usability Testing Patterns
Test Planning
Sample Size
- 5 users find ~85% of usability issues.
- 8-12 for quantitative confidence.
- Test with your target audience, not colleagues.
Task Design
- Scenario-based: "You want to send money to a friend who just bought you lunch."
- Not instruction-based: "Click the Send Money button in the top right."
- 5-7 tasks per session (30-45 minute sessions).
- Order from simple to complex.
Moderation
Questions to Ask
- "What are you thinking right now?"
- "What do you expect to happen?"
- "Is this what you expected?"
- "On a scale of 1-5, how easy was that?"
Questions to Avoid
- "Did you find that easy?" (leading)
- "Would you use this feature?" (hypothetical, unreliable)
- "Do you like the design?" (preference, not usability)
Rules
- Don't help. Let users struggle (that's data).
- Don't explain the design. If it needs explanation, it needs redesign.
- Follow up with "why" after observing behavior.
- Record sessions (with consent).
Analysis
- List all issues observed.
- Rate severity: critical (blocks task), major (causes confusion), minor (causes slight delay).
- Group by theme.
- Prioritize fixes by severity × frequency.