Developing User Interfaces for Microsoft Windows

There are two fundamental types of user testing:

• Design check A test made to check the usability of a user interface design during the design process. Such a test typically uses some kind of prototype, such as a paper prototype, a resource prototype, or a functional prototype. A design check is a good way to get early feedback to make sure that a difficult or unusual user interface design is going to work.
• Product check A test made to check the usability of production code as it nears completion as part of the testing and QA process. This type of test is best suited for fine-tuning a user interface by finding small problems. Programmer testing and QA testing should be performed before this test to remove any obvious problems.

Do not use the placement of this chapter within this book as a guide for when you should perform user testing. You can perform user testing as needed at any time during the development process, not just toward the end. Typically, you'll need to perform user testing during the design phase and the QA phase.

While I've mentioned in Chapter 8, "Users Aren't Designers" and Chapter 14, "Prototype with Caution" that I have reservations about the effectiveness of functional prototypes, I am convinced that the only way to get useful information from a functional prototype is through user testing. You have to actually witness users trying to perform tasks with a functional prototype for it to have any value.