Chapter 10: Usability Tests

Overview

A one-on-one usability test can quickly reveal an immense amount of information about how people use a prototype, whether functional, mock-up, or just paper. Usability testing is probably the fastest and easiest way to tease out show stopping usability problems before a product launches.

Usability tests are structured interviews focused on specific features in an interface prototype. The heart of the interview is a series of tasks that are performed by the interface's evaluator (typically, a person who matches the product's ideal audience). Tapes and notes from the interview are later analyzed for the evaluator's successes, misunderstandings, mistakes, and opinions. After a number of these tests have been performed, the observations are compared, and the most common issues are collected into a list of functionality and presentation problems.

Using usability tests, the development team can immediately see whether people understand their designs as they are supposed to understand them. Unfortunately, the technique has acquired the aura of a final check before the project is complete, and usability tests are often scheduled at the end of the development cycle—after the feature set has been locked, the target markets have been determined, and the product is ready for shipping. Although testing can certainly provide insight into the next revision of the product, the full power of the technique remains untapped. They can be better used much earlier, providing feedback throughout the development cycle, both to check the usability of specific features and to investigate new ideas and evaluate hunches.