Glossary » user testing
a family of methods for evaluating a user interface by collecting data from people actually using the system.
A simple user test would be to bring in a small number of potential users of the software (4-5 minimum, 8-10 to be thorough, more if the problem space or audience is diverse) and have each person sit down and use the software to perform a series of tasks while an observer takes notes about what difficulties each user encounters. Typically, users are asked to think out loud while they work with the software to help the observers understand how the users think about their problems and how the interface could be improved.
More involved user testing may test more users, get as representative a selection of users as possible, try out a variety of tasks, control the testing environment in various ways (or test a more naturalistic work environment), use more careful or thorough measurement instruments (videotaping, recording keystrokes, etc.), or combine the testing with other methods of data collection, such as interviews of users.