Useability Testing Is Critical to a User Centered Design

Useability testing is critical to making a successful user centered design. It doesn't test for questions like, is this product valuable to a customer? The hypothesis validation you did in chapter four should have answered that type of question. If you're testing a new feature in isolation from the main pro with a prototype, useability testing won't test whether existing customers are able to find and use it. A great design team will also think about the future and the road map. And this might lead to making choices in the current product that seem weird, but are better for the future.