By the end of this lesson you can
- Write a test plan with goals, participants, tasks and logistics.
- Choose what to test and what success looks like.
- Prepare materials so sessions run smoothly.
The idea
A usability test watches real people try to complete realistic tasks with a design, to find where it causes problems. Good tests start with a plan.
A test plan includes
- Goals and research questions: what you need to learn. "Can first-time users book a repeat prescription?"
- What is being tested: prototype, live site, competitor.
- Participants: who, how many and how they will be recruited.
- Method: moderated or unmoderated, remote or in person.
- Tasks and scenarios: realistic, in order.
- Success measures: task completion, time, errors, confidence ratings.
- Logistics: schedule, tools, consent forms, incentives, roles (moderator, note-taker, observers).
How many participants?
For finding problems in qualitative tests, around five participants per distinct user group usually reveals most major issues. Test, fix, and test again rather than running one large study. Quantitative benchmarks need many more participants.
Pilot
Always run a pilot session with a colleague to catch broken prototypes, confusing tasks and timing problems.
Why it matters in real projects
A plan keeps the test focused on decisions the team needs to make, makes sessions consistent so results are comparable, and lets stakeholders agree goals in advance. Skipping planning leads to vague findings and wasted participant time.
A realistic example
A pharmacy app team plans a test of a new repeat prescription flow. Goals: can first-time users find and complete a repeat order, and do they understand when it will be ready? Five participants who take regular medication, recruited through a panel, in 45-minute remote moderated sessions. Four tasks, with success measured by completion and a confidence rating.
The pilot with a colleague reveals the prototype breaks if someone taps "Change pharmacy", so they fix it before the real sessions.
Step by step
Agree goals
Write two to four research questions with stakeholders.
Choose method
Decide moderated or unmoderated, remote or in person.
Define participants
Write criteria and numbers.
Write tasks
Create realistic tasks linked to goals.
Define success
Choose what you will measure.
Prepare and pilot
Prepare consent, scripts and tools; run a pilot.
Common mistakes
Mistake No clear goals.
Instead Write research questions linked to decisions.
Mistake Skipping the pilot.
Instead Always pilot to catch problems.
Mistake One huge test at the end.
Instead Test small and often.
Check your understanding
Choose an answer, then check it. There is an explanation either way.
Practice exercise
Exercise · about 1 h
Test plan
Write a test plan for a prototype you built earlier.
Steps
- Write goals and research questions.
- Define participants and method.
- Write four tasks and success measures.
- Run a pilot and update the plan.
Deliverable
A one-to-two-page test plan.
Self-assessment
Tick each item when it is true of your exercise. Be honest; this is for you.
4 items
Summary
- Usability tests watch people attempt realistic tasks.
- Plan goals, participants, method, tasks, measures and logistics.
- About five people per group finds most major issues.
- Pilot before real sessions.
Further reading
Third-party sources, chosen for reliability. They open in a new tab.
- Usability testing 101 (opens in a new tab)Nielsen Norman Group
- Why you only need to test with 5 users (opens in a new tab)Nielsen Norman Group
Your notes
Marking complete updates your course and roadmap progress.