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Accessibility vs. Usability: There IS a Difference

By Ahmat Djouma and Nikhil Vohra

“Accessibility” and “usability” are two words that are often used interchangeably in the digital world.  However, there are important distinctions. On the web, accessibility refers to the ability of users with a range of disabilities—such as visual, auditory, or motor impairments—to properly access, interact with, and use online content and information.  Usability, on the other hand, is concerned with user experience, and it often refers to convenience, helpfulness, and compatibility.  Your website or web application may be accessible in that it meets minimum accessibility standards (such as the Web Content Accessibility Guidelines), but it may not be very usable in a practical sense. For example, important diagrams in a web article that lack alt text are left inaccessible to blind site visitors, as it can result in incomplete or missing information for those who rely entirely on screen readers. A lack of heading structure in a digital document, on the other hand, provided that the document text itself is still readable to screen readers, presents a usability issue (not necessarily an accessibility issue). Last week, we at the bulletin discussed web accessibility as it pertains to Federal government websites, and we mentioned two sites that meet or exceed mandatory accessibility guidelines: WhiteHouse.gov and CDC.gov. When distinguishing between accessibility and usability, however, these two sites stand in contrast to one another. Specifically, the White House’s website is both accessible and usable, providing convenient and useful heading structure and contrast options, among other features. The CDC website, although it may technically meet minimum web accessibility standards, provides no heading structure on its homepage, potentially making navigation tedious (particularly for those unfamiliar with the site). One way to ensure both accessibility and usability is to familiarize yourself with both concepts in order to be able to design web content that satisfies both principles from the start. In addition, you can employ beta testers to assess both accessibility and usability for your web content before publishing it or to improve it. To learn more about these concepts and the distinction between them, you can read an excellent blog post on the matter from the Bureau of Internet Accessibility.