Usability Testing
Usability testing means watching someone attempt a real task with a product, without helping them, to find where the design causes confusion.
The people who build a product cannot judge whether it is usable. They know the terminology and where everything lives, and that knowledge cannot be unlearned. Testing borrows the eyes of someone who does not have it.
How it works
A moderator sets a task, then stops talking. The participant attempts it while thinking aloud. The moderator watches and resists the strong urge to help.
That restraint is the whole method. The moment someone says "it is in the top right", the finding is destroyed, and the finding was the point.
Afterwards, patterns across participants get written down specifically enough to act on. "Three of five people looked in the main navigation before finding settings under the profile menu" is something a team can fix. "Navigation was confusing" is not.
Types
- Moderated. A researcher runs the session live and can follow surprises. Richest data, slowest to arrange.
- Unmoderated. Software sets the task and records the screen. Faster and cheaper, but you cannot ask why someone did something.
- Remote. Now the default. Removes geography as a limit on who you can recruit.
- In person. Still worth it when physical context or subtle hesitation matters.
- Guerrilla. Approaching people informally in a public place. Fast and rough, unsuitable when you need a specific type of user.
Common mistakes
- Helping. Every hint erases the problem you were there to find.
- Testing too late. A prototype is the cheapest place to discover a structural mistake. After launch is the most expensive.
- Letting the participant feel judged. Say plainly at the start that the product is being tested and they cannot get it wrong. People who feel examined stop behaving normally.
Key takeaways
- Say plainly that the product is being tested, not the person.
- Silence from the moderator is the method, not awkwardness.
- Report the specific behaviour you saw, never a summary judgement.
- Test on a sketch. It is cheapest to fix before anything is built.
Learn this
Lessons and exercises mapped to this concept.
Common questions
- How does usability testing differ from a user interview?
- An interview asks people about their experience. Usability testing watches them have one. Interviews are right for motivation, context and history. Testing is right for whether an interface works, because what someone says they would do and what they actually do routinely differ.
- Can I test something that has not been built yet?
- Yes, and it is usually the best moment. Paper sketches and clickable wireframes surface navigation, labelling and hierarchy problems perfectly well. The roughness helps: a team is far more willing to throw away a sketch than something that already looks finished, which is exactly the response a serious finding should get.
- Is five participants really enough?
- For finding problems in one group of users, yes, because the same issues start repeating quickly. For claiming a proportion, no. Saying four of five people struggled describes those five people. It does not mean eighty percent of your users will struggle.