Why You Only Need to Test with 5 Users

Usability is a quality attribute that assesses how easy user interfaces are to use.

In a usability-testing session, a researcher (called a “facilitator” or a “moderator”) asks a participant to perform tasks, usually using one or more specific user interfaces. While the participant completes each task, the researcher observes the participant’s behavior and listens for feedback.

Zero users give zero insights.

15 users discover almost all usability problems

Add more and more users, you learn less and less because you will keep seeing the same things again and again

3 tests with 5 users each

https://www.nngroup.com/articles/why-you-only-need-to-test-with-5-users/