Usability Testing
A user research method where participants attempt real tasks on a product while researchers observe — revealing where users struggle, get confused, or fail to complete their goals.
What is Usability Testing?
Usability testing is observing real users attempt specific tasks on your product (or prototype) to identify where they struggle, get confused, or fail. The goal is not to get opinions — it's to observe behaviour.
The key rule: don't help. When a user gets stuck, observe. The confusion is the data.
Types of usability testing
| Type | Description | When |
|---|---|---|
| Moderated | Researcher observes and probes live | Discovery, early prototypes |
| Unmoderated | Users complete tasks on their own (recorded) | Later-stage, higher volume |
| Remote | Conducted via Zoom or tool like UserTesting | Most common in practice |
| In-person | Researcher is physically present | Complex tasks, lab settings |
How to write usability test tasks
Bad task: "Find the settings page and update your notification preferences."
(Tells the user what to do — doesn't test if they can find it.)
Good task: "You've been getting too many emails from the app and want to stop them. Show me what you'd do."
(Mimics a real motivation — tests whether users can accomplish the goal without being told how.)
What to measure
- Task completion rate — % of users who finish the task
- Time on task — how long it took
- Error rate — wrong clicks, backtracking
- Satisfaction — post-task rating (Single Ease Question: 1–7)
Free templates for Usability
Frequently asked questions
How many participants do you need?
5 per round is the Nielsen guideline for moderated testing — enough to catch 80–85% of major usability issues. For unmoderated tests you need 20–30+ for statistical reliability. Run iterative rounds of 5 rather than one large study.
What's the difference between usability testing and user interviews?
User interviews uncover motivations, problems, and mental models through conversation. Usability testing reveals how users interact with a specific interface through observation. Use interviews for discovery; use usability testing for validation of designs.
Apply Usability Testing to your real product data
PMRead ingests customer feedback, interviews, and Slack threads — and generates PRDs grounded in real evidence.
Related terms
UX (User Experience)
The overall quality of a user's interaction with a product — encompassing usability, accessibility, performance, and emotional response — not just visual design.
Wireframe
A low-fidelity visual representation of a product screen that shows layout and structure without visual design — used to communicate information architecture and user flows early in the design process.
Prototype
A simulated version of a product or feature — ranging from paper sketches to clickable Figma flows — used to test ideas with users before engineering investment.