https://www.nngroup.com/articles/usability-testing-101/
Why Usability Test?
The goals of usability testing vary by study, but they usually include:
- Identifying problems in the design of the product or service
- Uncovering opportunities to improve
- Learning about the target user’s behavior and preferences
Why do we need to do usability testing? Won’t a good professional UX designer know how to design a great user interface? Even the best UX designers can’t design a perfect — or even good enough — user experience without iterative design driven by observations of real users and of their interactions with the design.
There are many variables in designing a modern user interface and there are even more variables in the human brain. The total number of combinations is huge. The only way to get UX design right is to test it.