1999 Conference Proceedings

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Universal Design of a Web Site

Michael Cooper - CAST
39 Cross St.
Peabody, MA 01960


CAST was founded to study and develop ways technology can be used to enable people with disabilities, especially in educational environments, to participate in the mainstream. In recent years, CAST has refined the concept of universal design, a term borrowed from architecture. Universal design of technology refers to software and hardware features that are created with a wide range of users in mind. Universally designed products reduce the need for multiple products targeted to different populations; instead, one product can benefit users with a wide range of needs and preferences. In education, students gain extra benefit from the multiple ways of interacting with the technology. More on the concept of Universal design for learning is available at http://www.cast.org/concepts/.

CAST's Bobby (SM)

While developing universally designed software products, CAST found that products using Web pages rely on universal design features of those pages. To help authors incorporate those features into their pages, CAST created Bobby (http://www.cast.org/bobby/). This free software examines the structure of HTML pages and notes technical or design issues that may present barriers to persons with disabilities who access the site. The tool has helped thousands of users and organizations make significant improvements to their web sites. These people have in the process been educated about universal design principles and now incorporate universal design into every aspect of their web site development.

Bobby, now in beta of version 3, uses the latest available guidelines from the Page Author Guidelines Working Group (http://www.w3c.org/WAI/GL/) of the Web Accessibility Initiative at the World Wide Web Consortium. The guidelines are a prioritized set of design and technical recommendations for page authors. Many recommendations are for alternate representations of media, such as alt-text and descriptions for images; others help authors avoid problems encountered by persons using access aids or non-standard browsers.

Bobby can test most of these guidelines, detecting the presence or absence of certain features. Since it is an automated program, it cannot test some that require a judgement call. Bobby identifies these potential issues and presents them as recommendations and tips. Some tips also relate to enhancements possible in HTML 4.0 that are not yet required because the current generation of browsers does not implement them.

In addition to design problems that may impact persons with disabilities, Bobby also tests for variations in browser compatibility. Many web browsers exist, and in many versions that implement different subsets and versions of HTML. These browsers also often recognize tags that are not part of the HTML language and are not useable by other browsers. Because of the wide variation in the market, and because many users choose to use older browsers because they have old hardware or slow network connections, it is important to design pages that can be viewed adequately in this environment as well.

Testing for these issues broadens the definition of "universal design" of web pages. It also widens the market for Bobby, as more web designers are concerned about browser compatibility than accessibility. Since an accessibility check is always part of Bobby's operation, regardless of how else it is used, designers are presented with that information. In this way, Bobby educates designers about issues that they often were not aware of. CAST hears regularly from these designers who thank us for introducing them to the concept of accessibility and have begun integrating those principles into their sites. Bobby has been very successful as an educational tool when used in this way.

CAST Web Site

In July 1998, CAST released a major update to its web site (http://www.cast.org/). The revised site is an educational resource about the principles of universal design. As such, a major goal was to create a model of universal design on the Web. The site needed to be accessible to as wide an audience as possible, with different physical, learning, motivational, and experiential backgrounds.

Bobby was an important tool to the many people who contributed content to this site. As it grew, Bobby informed developers of potential problems that they could fix. Over time, it became easy to create new pages that were already accessible without the need for retrofitting. Bobby was successful in its goal of being an educational resource within CAST.

Design Features

A page on the CAST web site, http://www.cast.org/site_about.html, describes the universal design features of the site. Many of these involve visual design, such as redundant identification of sections by text, color, and shape of icons. The use of tables for layout involves an intersection between visual design and technical design. The layout of pages is such that non-presentation of a table, as in Lynx, or inability of access aids such as screen readers to detect table structure and present text accordingly, does not create an access barrier.

An important part of universal design is multiple representations of content (http://www.cast.org/concepts/concepts_three_p.htm). The CAST web site accomplishes this in part through the use of ALT-text behind images and links in image maps. Images also have longer descriptions, provided through the use of d-links and, in anticipation of future browser compatibility, the LONGDESC attribute (see http://www.cast.org/strategies/exploration/image/ for information on describing images). Sounds have descriptions or transcripts, and videos are both described and captioned.

Flexibility of content is important to universal design of content, as it maximizes the ability of software on a client to present information in a user's preferred way. This is accomplished on the CAST site by appropriate use of HTML structural elements, such as headings that can be converted into a dynamic outline on the client. Structure can also be added to the page by dividing it into sections through use of the new DIV element - CAST's pages are divided into header, navigation, body, and footer sections.

HTML 4.0 provides the potential for a number of user interface enhancements, some of which are already implemented by some browsers. CAST has incorporated these into its site as well. These include access keys, which allow users to follow links by pressing a keyboard shortcut instead of using the mouse or tabbing among links. Because not all links can be assigned a keyboard shortcut, it is also possible for authors to specify a logical tab order among links that determines the order in which links can be viewed by pressing the tab key repeatedly. CAST has used this feature to group links, so all navigational links are adjacent in the tab order, and references in the body are also adjacent and presented before navigation although they appear later in the document structure.


Universal design is an important approach to addressing accessibility issues in technology. Bobby was created to encourage universal web page design by checking pages for potential problems and teaching authors how to resolve them. Many developers learn about accessibility issues when they use Bobby to validate their HTML for various browsers and use Bobby's graphic download time assessment. The tool was used by CAST as it developed its new model, universally designed web site. CAST continues to use the venue of its web site, combined with the success of Bobby, to support and encourage other developers to produce universally designed technology.

Michael Cooper
39 Cross St
Peabody, MA 01960
978 531 8555 x265

Bobby Approved

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