How to conduct a usability test on 5 users?

Usability testing with 5 users is conducted as follows:

1. Define the test goal — what exactly you want to check (for example, registration convenience).
2. Prepare scenarios — simple tasks that the user must perform.
3. Select 5 representatives of the target audience — different in experience and behavior.
4. Conduct sessions one by one — observe how the user performs tasks, do not help, record problems.
5. Gather feedback — ask questions about impressions.
6. Analyze the results — identify recurring problems encountered by multiple users.

Five users are enough to identify about 80% of the main interface issues, as errors often repeat.