Usability testing is a method by which users of a product are asked to perform certain tasks in an effort to measure the product's ease-of-use, task time, and the user's perception of the experience. Changes are made to the application or site based on the findings of the usability tests. Usability test participants are encouraged to think aloud and voice their every opinion. Usability testing is best used in conjunction with a user-centered design process, a method by which a product is designed according to the needs and specifications of users.
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Depends on which phase of the development cycle- what can be changed? Conceptual model? Layout? Fonts?
There should be a list of questions of the major design issues that is prepared in advance. There should be specific question(s) that the usability testing is designed to answer. Usability testing has specific objectives.
During a usability test, instruct participants to verbalize their thoughts aloud protocol. The usability testers prompt participants by asking direct questions about the software, in order to understand their mental model of the system and the tasks, and where they have trouble in understanding and using the system.
During a usability test, two participants perform tasks together while being observed. In order to increase the amount of communication to gain insight to their thought process, one participant is assigned the mouse and the other the keyboard. They are to help each other in the same manner as they would if they were working together to accomplish a common goal using the product.