Use when
- You need to know whether users can complete important tasks.
- You need direct evidence about confusion, errors, or mismatched expectations.
- You are testing designs, prototypes, or live-product flows.
Best for
- Onboarding and registration
- Critical journeys
- Trust and error handling
How to design it
- Use realistic tasks and scenarios.
- Encourage participants to think aloud without coaching them through the task.
- Record completion, confusion, errors, and confidence, not just opinions at the end.
Suggested sample size
Start with 5 to 8 participants in a priority segment, then add more if the audience is highly varied.
Usability Test Plan TemplateUse this when you need a practical reading template.
View template
- What key task must the user complete?
- What success or failure indicators will be observed?
- What prompts are needed if the participant gets stuck?
- How will findings be prioritized after the session?
Typical output
- Usability findings list
- Severity and evidence summary
- Flow improvement recommendations
Useful resources
Nielsen Norman GroupUsability Testing 101
Primary method guidance for observing task completion, errors, and opportunities.
GOV.UK Service ManualUsing moderated usability testingPractical session guidance for moderated testing with prototypes or live services.
Nielsen Norman GroupWhy You Only Need to Test with 5 UsersUseful sample-size framing for small, iterative qualitative usability testing.