The DO-IT (Disabilities, Opportunities, Internetworking, and Technology) Center, based out of the University of Washington’s Seattle campus, produced a useful document outlining the differences between accessible design, usable design, and universal design. These three concepts can apply to built environments, information technology, products, and education.
Accessible design takes into account the needs of everyone including people with disabilities. An accessible product, service, or building can be conveniently used by a variety of individuals. Universal design is concerned with creating technology and environments that can be used by as many people as possible without the need for adaptation. In the process of universal design, human factors such as age, gender, stature, culture, language, and learning style, as well as disability, are considered. Usable design is, naturally, intended to create products that are easy to use. Usability testing with a sample of users influences design; however, testers do not always include people with disabilities in usability tests. Accessibility is increasingly being considered in the area of usable design, in addition to consistency and efficiency.
It is useful to understand the distinctions between accessible, universal, and usable design. Applying universal design, with attention to accessibility, and conducting usability testing with a diverse group can help designers to create items and spaces that are useful to as many people as possible.