Not all usability tests are created equal. As important as it is for companies to undergo testing in the first place, its just as critical for them to time testing to match the stages of a Web sites development.
"The essence of usability testing is feedback," said Phil Goddard, chief of training, development and delivery at usability lab Human Factors International Inc., in Fairfield, Iowa. "You want the right kind of feedback to move to the next phase of design. You need feedback early and continuously."
Goddard divides a typical Web development project into three stages, each requiring different usability tests. They are:
Exploratory testing. From the beginning, site developers must avoid the urge to rush into creating a working prototype. Doing so limits developers willingness to make significant changes because of the time and money already invested in a functional prototype. Rather, at this stage, developers should focus on gathering the perceptions of users. Tests should focus on users opinions about brand, the overall flow of tasks through a site and the basic hierarchy.
Prototype testing. Even at this stage, its best to begin with hand sketches and mock-ups, rather than a working prototype. "It encourages critiques from users because they know its at a crude level and its easy to change," Goddard said. From sketches and mock-ups, developers can move into creating a functional prototype and can conduct formal, one-on-one performance tests where users are asked to complete tasks on a site.
Production-level testing. At this point, the prototype has become a living, breathing site with more detailed navigation, content, and a definite look and feel. Developers also become more resistant to major changes, Goddard said. Another set of performance lab tests should be conducted, this time with more measurements of factors such as the number of steps required to complete common tasks and the rate at which users encounter errors. From there, consistency becomes critical. Companies should consider developing formal style guides that set out the proper fonts to use, where to place graphics and how to incorporate photos, Goddard said.
A multistep approach to usability testing, rather than a last-minute one, allows companies to measure the results of changes made from earlier tests and to prevent themselves from wasting millions of dollars on a design before finding out that users hate it, said Randolph Bias, chief usability officer at Austin Usability Inc., in Austin, Texas.
"The [return on investment] for your usability dollar and hour is more robust if you pay attention to usability throughout the development cycle," Bias said. "Its important for Web development teams not to rely on their own intuitions of what is usable or not. Theyre not representative of their audience."