Much thought and effort go into the conceptualization, development, production, and marketing of new products. Nonetheless, users may have difficulty using the product as intended, for a whole host of reasons. The impetus behind usability assessments is to understand the source of these use challenges throughout every stage of the process, so as to improve the design or instructional support and fulfill the potential of the products. Note that we will use the term “product” in this chapter as shorthand; similar methods apply for environments, systems, training programs, websites, etc. – the main ideas are the same. Moreover, the basics of the different usability methods are constant regardless of the user group, but there may be nuances that are specific to older adult users. We will highlight these in the case studies with older adults provided in this chapter.