How does accessible web design benefit all Web users?
There are many examples in society of innovations that were originally intended for people with disabilities but that have provided access benefits to all people (curb cuts and automatic door openers are two of the most common). Accessible web content is a similar innovation. Web content designed in a way that is accessible to people with disabilities additionally benefits many non disabled users and often benefits all users. Following are specific examples:
- Providing text alternatives to visual
(e.g., providing ALT text for images) benefits anyone who doesn't have
immediate access to graphics. While this group includes people with
blindness, it also includes those sighted computer users who surf the
Web using text-based browsers such as Lynx.
Text-based browsers have a loyal following because they provide quick
and efficient access to web content. Also, despite the increasing
availability of high-bandwidth accessible technologies, it still isn't
ubiquitous, and many Internet users are still connecting using regular
dial-up telephone lines due to lack of available alternatives
(particularly in rural areas), income, or choice. Slow-loading graphics
can seriously impede these users, and many have learned to disable the
display of graphics in their browser in order to decrease download
times. Similarly, users of hand-held computing devices often disable
graphics in their browsers to facilitate quicker downloads, to conserve
memory, and to ensure a better fit in the small browser window.
There is also a growing market for voice web and web portal systems, which provide text-to-speech web access via telephone or car (for examples, see Audiopoint, InternetSpeech, and SmartWeb Vehicle, as described in the WebWired article Ask your car radio!). Some of these technologies currently provide specific services through a small group of elite content providers, while others already provide full access to the web. Access for users of these services depends on the availability of text alternatives to visual content, as well as other accessible web design techniques.
- Providing text alternatives to audio content (e.g., including captions with multimedia) allows access to people with limited or no access to sound output. This includes people who are deaf or hard of hearing, but it additionally includes anyone trying to access the content in a noisy environment and people with missing, broken, or otherwise inadequate sound hardware. Captioned multimedia also allows the content to be indexed and archived so that it is fully searchable. A growing number of organizations are developing video search applications based on closed captions. For an example see UC Davis Broadcast News & Information.
- Avoiding use of color to convey essential information ensures that the information is accessible to those who can't reliably discriminate between colors. This group includes people with blindness and color blindness, but it also includes people using monochrome monitors and hand-held computers with green screens. It also benefits people who are using voice web services, as described above.
- Using high-contrast foreground/background colors benefits those with visual impairments, but most other users will also enjoy reading your site without squinting or experiencing eye fatigue.
- Using cascading style sheets (CSS) rather than HTML tables to control layout of web pages results in pages that are more usable for screen reader users, but additionally allows content to be displayed more appropriately on smaller screens and on emerging web-enabled devices such as wireless phones.
- Using relative rather than absolute units (e.g., percentages, 'ems', instead of pixels) ensures that content fits well regardless of resolution, and more importantly allows the user to re-size the text.. Users with and without disabilities have an ever-increasing choice of resolution settings with modern computer equipment. Content should be designed to scale reliably, regardless of users' display devices or settings.
- Clarifying natural language usage (i.e., specifying whether the language of your content is English, Spanish, or some other language) allows supporting screen readers to use the appropriate language engine automatically to read the content synthetically. This, of course, benefits screen reader users such as people with blindness or reading disabilities. However, it also allows search engines to index your content by language more accurately. In addition, specifying a change in language mid-paragraph helps prevent confusion when screen readers are providing content.
- Avoiding flashing animation is necessary as animations that flash at frequencies between 2 and 55 hertz can trigger seizures in individuals who are susceptible. Flashing animations, however, additionally tend to annoy or distract users without seizure disorders.
- Providing a clear, simple, and consistent design, including an intuitive navigational mechanism, benefits a variety of users with disabilities, but the result of doing so is a web site where users can easily and efficiently find the information they're looking for. Clearly, this is a benefit to all users.
People access the Web using a growing variety of technologies, customized with a growing variety of possible preferences and configurations, and people with disabilities are included in this mix. By recognizing that this technological diversity exists and by developing web content that complies with standards such as the World Wide Web Consortium's Web Content Accessibility Guidelines, web authors can ensure that their web sites are accessible to the broadest possible audience.