The Technology Tips column in the December 1995 issue of DO-IT News gave an overview of what the World Wide Web is and why it is such a powerful and flexible Internet resource. This issue's column discusses how to design Web pages that are accessible to all potential users, regardless of disability.
DO-IT's Web Design Philosophy
The varied features of the World Wide Web are attractive to a wide variety of users. Yet many Internet surfers are unable to view graphics and photos because of visual impairments, or cannot hear audio because of hearing impairments. DO-IT's philosophy in designing its pages is to practice "universal design" principles so that all visitors to our Web pages can access its content. Universal design means we concentrate on content rather than flashy graphics and audio and consider the full spectrum of potential users. When designing a document, we attempt to make the material, whether it is a menu item, graphic, or video clip, as accessible as possible.
Web developers should be aware that a diverse group of people may visit your Web pages. Some visitors:
- 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
Perhaps the most important consideration in designing Web pages is to not require that a Web site visitor use a specific browser to access information. Numerous Web sites require the use of a particular version of Netscape. Though this is the most popular browser currently used, developers should acknowledge that it's not the only option. For Web site developers, accessibility to the maximum number of potential customers should be a top priority.
Many of the accessibility issues and tips described below make a favorable impression for all Web users, regardless of disabilities or special needs.
General Web Design Tips
- Maintain a simple, standard page layout throughout the document.
Once a method of layout is determined for your page(s), stick with it. A consistent interface for your pages will make it easier for anyone contacting your site to find and access information. Buttons and navigational links should always appear in the same places (top, bottom or both) on a page, and headers should follow a consistent format.
Who Benefits? Everyone, particularly people with learning and visual impairments and for whom English is a second language. Consistency and simplicity are the keys to accessibility.
- Use universally recognized HTML tags.
Don't use formatting tags (such as <BLINK>) that are only supported by one Web browser. The HTML version 2.0 standard is the best bet for compatibility with a wide variety of Web browsers.
Who Benefits? Anyone using a text-based browser, particularly users who are blind.
- Test your pages with a variety of Web browsers.
Test your Web pages on at least three different Web browsers. One of the browsers tested should be a text-based program such as Lynx. This 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 (Macintosh, PC and X). Though it is possible, with some programming on the server side, to determine what browser someone is using and make certain types of information available, most developers do not have the resources available to do this.
Who Benefits? All potential Web site visitors.
- Provide alternate text for browsers that can't display images.
Many people cannot see pictures or drawings. This can be due to a disability or as a result of using a text-based browser. The <ALT> tag when used with a graphic will allow a written description of the image to be conveyed to the user. The <ALT> tag is an excellent way to make a graphical button accessible to those using text-based browsers. Also, for those developers using graphical bullets, an ALT tag can contain other text that provides a good alternative such as an asterisk or text.
Who Benefits? Users who cannot see images.
- Avoid using tables.
Tables are not supported by all browsers and can be confusing for people using voice output to read. Screen reading software cannot differentiate between columns so that text is read constantly from left to right.
Who Benefits? Anyone using a browser that doesn't support tables and anyone 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-based 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.
Who Benefits? Visitors who may be blind and/or deaf.
- Provide text alternatives to image maps.
Image maps are graphics that 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-based alternative.
Who Benefits? Anyone using a browser without graphics capability, those who cannot see images, and users who have turned off loading of graphics.
- Don't use complicated backgrounds.
Many backgrounds do not provide enough contrast for easy viewing. Users with visual impairments often invert their screen colors due to light sensitivity or other needs. Backgrounds and other formatting that changes the color of text can make a page inaccessible to someone with a visual impairment or for someone with a reading impairment. If a custom background must be used, select something that provides good contrast with your text.
Who Benefits? Visitors with visual impairments and people accessing via slower connections.
Issues related to design and specific disability types are discussed at www.washington.edu/accessibility/checklist/. Many of the tips provided in this publication were found at this useful site.