Book excerpt: Whether it's software, a cell phone, or a refrigerator, your customer wants - no, expects - your product to be easy to use. This fully revised handbook provides clear, step-by-step guidelines to help you test your product for usability. Completely updated with current industry best practices, it can give you that all-important marketplace advantage: products that perform the way users expect. You'll learn to recognize factors that limit usability, decide where testing should occur, set up a test plan to assess goals for your product's usability, and more.