Zero users give zero insights.
Testing to find usability issues is never a waste, no matter your budget.
Because zero users give zero insights.
Five people find more than 75% of the issues in the current version of a design.
So you only need a few people for usability testing?
Just a few people will give you very valuable insights. But I recommend testing as many people as possible. Just not all at once. It’s best to test with a small group of people – iterate your design and test again. I value usability testing across many small tests.
The essential things that help me to improve the usability of my designs are:
If you target multiple distinct user groups. You need more participants for each round of testing. You only need a few if your target audience is interacting with your design in similar ways.
Insightful usability testing does not have to be very expensive and complex.