Making Web Sites Accessible To All:

Dan Comden
Dagmar Amtmann
University of Washington

Web Posted on: November 22, 1997

The dramatic growth of the internet and World Wide Web (WWW) make it possible for people throughout the world to access information as never before. Ensuring equitable access to electronic information is a topic that may not be addressed by all maintainers and producers of electronic information. This paper summarizes guidelines that can be employed to make WWW resources available to the full spectrum of people who may visit a web site.

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. If "universal design" principles are employed, all visitors to Web pages can access the content. 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 are made as accessible as possible.

As a Web developer, you should consider the diverse abilities of people who 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 make sure that a Web site visitor is not required to use a specific browser to access the information provided at that site. Presently it's not uncommon to find Web sites that require the use of a particular web browser (commonly Netscape Navigator or Internet Explorer). Although a browser's popularity may predispose a web designer to use the features and abilities that pertain to that package, one must be aware of the entire spectrum of potential web site visitors. This can include older or non-standard browsers and text-based browsers. Also, connection speed often dictates what browser a person may use; text-based browsers can load and display web pages significantly faster and with less overhead than the current popular web browsing packages. 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.

General Web Design Tips

• Maintain a simple, standard page layout throughout a 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: Just about everyone benefits when Web developers follow this guideline, but particularly people with learning and visual impairments and for whom English is a second language. Consistency and simplicity are 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: Everyone using a text-based browser, particularly those who are blind.

• Test your pages with a variety of Web browsers. A minimum of three browsers are recommended for testing purposes, preferably on two different platforms. One of the browsers tested 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). 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 will benefit when this guideline is followed.

• 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: 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 to read text on the screen. Screen reading software cannot differentiate between columns so that text is read constantly from left to right. Some techniques involving use of tables, mainly using paragraph breaks (the <P> tag) in strategic locations, can help make tables more readable.

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 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: Web site 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. Unless the newest version of web server software is utilized at your site, there is no other method of making image maps accessible.

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. 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: Site visitors with visual impairments and people accessing via slower connections.

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. From a marketing standpoint, it makes sense to allow the widest potential audience access to your site. This is important for commercial enterprises but also other free repositories of information. Web designers are in a unique position to demonstrate universal access features and to provide universal access to information resources

DO-IT Resources

A videotape and handout titled "World Wide Access" is available through the DO-IT program for $20. A good launching point to find resources for making accessible Web pages is the DO-IT HTML Guideline page at

http://weber.u.washington.edu/~doit/Other/design.html

DO-IT (Disabilities, Opportunities, Internetworking and Technology) is primarily funded by the National Science Foundation. Additional funds for helping libraries make electronic resources accessible to people with disabilities are provided by the Telecommunications Funding Partnership.

DO-IT University of Washington
4545 15th. Avenue N.E.
Seattle, WA 98105
Voice/TDD (206) 685-DOIT
FAX (206) 685-4045
doit@u.washington.edu
http://weber.u.washington.edu/~doit/