Test, Test, and Retest
The design of graphical systems and Web pages, and their screens, is a complicated process. As has been shown, in both a host of factors must be considered. In graphical systems, among the many design elements are the types of windows used, the way the windows are organized, what controls are selected to collect and present information, and the way the controls are organized within one window and between several windows. Web page design factors include the proper integration of text, graphics, navigation links, and controls, page size, writing for simplicity and clarity, the characteristics of browsers and monitors, and accessibility requirements. In both design processes numerous design trade-offs will be made. Also, some design decisions may be based on skimpy data and reflect the most educated guess possible at the moment. Finally, the implications for some design decisions may not be fully appreciated until the results can be seen.
To wait until after a system has been implemented to uncover and correct any system usability deficiencies can be aggravating, costly, and time-consuming for both users and developers. Indeed, after implementation many problems may never be corrected because of time constraints and costs. To minimize these kinds of problems and ensure usability, interfaces must be continually tested and refined before they are implemented.
What follows is an overview of the usability testing process and the role it plays in design. ...