DO-IT Creating a Level Playing Field for the World Wide Web
DO-IT: Creating a Level Playing Field For the World Wide Web
John, a high school student, cruises the Internet for information about potential colleges to attend. Blind since birth, he uses a text-based Web browser called Lynx. He has a screen reader and voice synthesizer on his computer so that the screen is read aloud. He encounters a Web site with a campus map and his speech synthesizer says "ISMAP." He has no way to access the information because it is in graphical form.
Samantha, an art history major at a university, finds a Web site with video clips that will be useful in developing her term paper. Unfortunately the videos are not captioned, so she cannot access the critical information she needs. She is deaf.
Duane, a salesman with a learning disability, has difficulty maneuvering through Web sites that are cluttered and use inconsistent formats.
George, who has limited use of his hands as a result of Cerebral Palsy, has little difficulty cruising the 'Net, until he encounters small buttons on the screen. His limited motor ability makes it difficult to "press" them.
The dramatic growth in availability of information on the World Wide Web, makes this a resource that a growing number of people need access to as part of their education, work and/or other life activities. With the developments in adaptive technology that make it possible for people with a variety of disabilities to access computers, the Internet has provided tremendous potential for equal and independent access to information.
Unfortunately, the multi-media features of the World Wide Web that make it attractive to many, create barriers to some. Some visitors to a Web site:
- cannot see graphics because of visual impairments.
- cannot hear audio because of hearing impairments.
- use slow connections and modems and choose not to view graphics.
- have difficulty when screens are unorganized, inconsistent and cluttered and when descriptions and instructions are unclear. These difficulties may occur because they have learning disabilities, English is their second language, or they may be younger than your average visitor.
To assure that all visitors to a Web site can access its content, principles of "universal design" should be employed. Universal design means to concentrate on content rather than flashy graphics and audio, and consider the full spectrum of potential users. Documents, menu items, graphics, video clips, and other materials should be made as accessible as possible. When designing a Web site, it is important to be aware that some visitors to the site may be using adaptive technology; steps should be taken to assure that they electronic resources at the site are accessible when using that technology.
With the advent of the World Wide Web, just about anyone can be a publisher -- companies, educational institutions, recreational facilities, home users. It is, therefore, important that everyone be aware of at least the most basic design features for making World Wide Web pages accessible to everyone. For Web site developers, accessibility to the maximum number of potential customers should be a top priority.
This article introduces a few of the basic design concepts. Many of the accessibility issues and tips presented make a favorable impression for all Web users, regardless of abilities and disabilities.
World Wide Web Design Tips
- Maintain a simple, consistent page layout throughout your site. Once a format is determined for your page(s), stick with it. Elements presented on every page, such as logos, buttons, and navigational links, should appear in the same places on the pages. Using a consistent format for your pages will make it easier for anyone visiting your site to find and access information, but especially people with learning and visual impairments and for whom English is a second language. Consistency and simplicity are keys to accessibility.
- Keep backgrounds simple. Many backgrounds to not provide enough contrast for easy viewing by users with visual impairments. If a custom background must be used, select something that provides good contrast with your text. Site visitors with visual impairments benefit when this guideline is followed.
- Design large buttons. Small buttons marking links can be a difficult target for visitors having mobility impairments that result in restricted hand movements. Larger buttons can make it easier for all visitors to select the links on your page.
- Provide alternate text for images. Many people cannot see pictures or drawings. This can be due to a disability, or be a result of using a text-based browser because of system limitations. The Web designer should make sure that an alternative written description appears on the screen when a text-based browser is used. Following this guideline benefits all Web site visitors who cannot see images, either because of blindness or because their Internet access method restricts them to using a text-based browser.
- Avoid using tables. Tables are not supported by all browsers and can be confusing for people using voice output systems to read text on the screen. Screen-reading software cannot differentiate between columns, so that text is read constantly from left to right. Applying this guideline benefits anyone using a browser that doesn't support tables, particularly those using voice output to read text.
- Avoid using a single mode of delivering information other than text. If information is to be conveyed using audio or video files, provide text alternatives. For example, if an audio file contains dialogue or lyrics, a transcript of the file will enable someone with a hearing impairment to access it. Also, video may contain information that can be provided in descriptive text form for someone who is blind. Web site visitors who are blind and/or deaf benefit when this guideline is followed.
- Provide text alternatives to image maps. Image maps are graphics which contain multiple areas that, when selected with a mouse or other pointer, jump to another Web page or section. The only method of making image maps accessible is to provide a text alternative. Anyone using a browser without graphics capability, those who cannot see images, and users who have turned off loading of graphics all benefit when this guideline is followed.
- Use standard HTML. Hypertext Markup Language (HTML) is the standardized code used to create Web sites. The code works with tags which tell the browser where to find and how to display your information. Avoid using tags (such as <BLINK>) that are only supported by one Web browser.
- Include a note about accessibility. Notify your users that you are concerned about accessibility and that you would like to be contacted when features at your site create barriers to visitors. For example, the DO-IT (Disabilities, Opportunities, Internetworking and Technology) home page includes the following statement:
The DO-IT pages form a living document and are regularly updated. We strive to make them universally accessible. You will notice that we minimize the use of graphics and photos, and provide descriptions of them when they are included. Video clips are open captioned, providing access to users who cannot hear. Suggestions for increasing the accessibility of these pages are welcome.
- Test your pages with a variety of Web browsers. Use at least three different Web browsers to test the accessibility of your Web pages. One of the browsers should be a text-based program such as Lynx. This testing will ensure that pages are accessible to people who may be using a different browser than you. If possible, also examine your pages using browsers on different platforms (e.g., Macintosh, PC, and X). You might want to try out an accessibility validation site which performs a diagnostic on your pages and points out parts that could be inaccessible. For example, "Bobby" is a program that will help you identify problematic features at your site. It was created at CAST (Center for Applied Special Technology) and can be found at: http://www.cast.org/bobby/.
When care is taken to assure that Web sites adhere to universal design principles, a larger audience of Internet users will be able to make use of the wealth of information resources on the Net.
Sheryl Burgstahler, Ph.D.
Adaptive Technology Specialist
University of Washington
Seattle, WA 98195-4842