At the heart of the design process is meeting the needs of the person who will be using whatever is being designed. Products, environments, and systems (simple or complex) will have end users and perhaps multiple groups of end users. Different stakeholders (i.e., user groups) must be considered in the design process – in this chapter we focus on older adults. We provide an overview of needs assessment techniques. Case studies are drawn from research on healthcare applications, digital home assistants, and design of personal robots.