By the end of this lesson you can
- Evaluate interaction prototypes with users and experts.
- Combine heuristic review with quick user testing.
- Turn evaluation results into prioritised changes.
The idea
Before handing interactions to development, evaluate them. Two complementary methods are quick and cheap:
Expert review
A heuristic evaluation checks the prototype against known principles, such as Nielsen's ten heuristics. Two or three reviewers work independently, then combine findings. It is fast and finds obvious problems, but it cannot tell you what real users will do.
Quick user testing
Give five or so people realistic tasks and watch them use the prototype. Note where they hesitate, misinterpret or fail. Ask them to think aloud. You will cover testing in depth in Stage 8.
What to look for in interactions
- Can people find and recognise controls?
- Do they predict outcomes correctly?
- Is feedback noticed and understood?
- Can they recover from errors?
- Does motion help or distract?
Prioritise
Rate each issue by severity (how badly it affects people) and frequency, then fix the most serious first.
Why it matters in real projects
Evaluating prototypes catches problems when they are cheap to fix. Combining expert review and user testing finds more issues than either alone. Clear, prioritised findings help the team agree what to change before development begins.
A realistic example
A team evaluates a new drag-and-drop calendar prototype. Heuristic review flags missing keyboard support and unclear undo. Testing with five people shows two cannot find how to move an appointment because the drag handle is too subtle, and one does not notice the confirmation.
The team prioritises: add a visible handle and a "Move" option in the event menu (also solving keyboard access), make confirmations persistent with undo, and leave a motion tweak for later.
Step by step
Prepare tasks
Write realistic tasks for the prototype.
Run a heuristic review
Have two or three people review independently.
Test with users
Watch five people complete tasks.
Combine findings
Merge and de-duplicate issues.
Rate severity
Rate each issue by impact and frequency.
Plan changes
Agree what to fix now, later or not at all.
Common mistakes
Mistake Only reviewing your own design.
Instead Include other reviewers and real users.
Mistake Treating every issue as equal.
Instead Rate severity and prioritise.
Mistake Testing with colleagues only.
Instead Test with people who match your users.
Check your understanding
Choose an answer, then check it. There is an explanation either way.
Practice exercise
Exercise · about 1 h 30 min
Evaluate a prototype
Evaluate the prototype you built in "Prototyping flows".
Steps
- Run a heuristic review with one other person.
- Test with three users.
- Combine and rate findings.
- Write a prioritised change list.
Deliverable
A findings table with severity and a change list.
Self-assessment
Tick each item when it is true of your exercise. Be honest; this is for you.
4 items
Summary
- Evaluate interactions before development.
- Heuristic reviews and user tests complement each other.
- Focus on findability, prediction, feedback and recovery.
- Prioritise by severity.
Further reading
Third-party sources, chosen for reliability. They open in a new tab.
- How to conduct a heuristic evaluation (opens in a new tab)Nielsen Norman Group
- 10 usability heuristics (opens in a new tab)Nielsen Norman Group
Your notes
Marking complete updates your course and roadmap progress.