Usability is the measure of how well a person can use a product to achieve an intended goal. In a previous post, I talked about how usability testing should be a key part of any iterative design process, preferably being implemented as early as possible to identify design problems. But usability testing is also an important tool to evaluate existing products before you ever sit down at the drawing board to devise a change or new design.
How do you test something that doesn’t exist? The obvious answer is to build it. But what if it’s difficult, time-consuming, and/or expensive to build? You don’t want to risk wasting resources on an untested idea. A common approach that user experience designers (UX) use in such situations is Wizard of Oz studies.