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...of the Web sites for United States government agencies, which have been mandated to be accessible by Section 508 (1) for over three years, meet Section 508 requirements. (2)
Even with management team commitment to Web accessibility standards, when a Web presence is large and has hundreds or even thousands of people and applications who contribute content to it, developing and managing standards compliance is complex. Naturally, it is desirable to start by building compliance at points of entry into the system. This can be aided by standardizing the suite of authoring and content management tools supported in the enterprise and through provision of templates that provide accessibility features. The first section of this paper describes innovative use of template technology that goes beyond providing compliance; the templates enable even complex sites to dramatically increase usability for people with disabilities.
There is no way, however, to control or even be aware of every point of entry into the Web space in order to block inaccessible content from entering. A compliance management system for a large enterprise first requires a content discovery mechanism. Web content discovery systems--known as "crawlers"--vary widely in scalability, performance, and reliability, and managing them is complex. Once discovered, content must then be analyzed for standards compliance. Several commercial products offer automated accessibility analyses of Web documents, and some of these products incorporate Web crawlers. These tools vary greatly in their performance and scalability.
After these automated tools discover and analyze Web content, results must be communicated. For some enterprises there may be reports on exorbitant numbers of Web documents addressed to different content owners, and reliably segmenting the report data into meaningful categories is very challenging.
For example, the automated tools may generate a report on 80,000 Web pages that is sent to the marketing department. This report may state that 30 percent of their content is not compliant, but 20,000 of these pages may actually be owned by the technical support organization. The second section of this paper describes how IBM has addressed these challenges in building an automated compliance monitoring system for its own internal and external Web spaces.
Fully automated compliance monitoring, though useful, cannot indicate whether documents comply with Web accessibility standards. It can only identify problems if the violations of standards are machine-detectable. In fact, more than half of the provisions included in most standards sets, for example, U.S. Section 508 (1) or the World Wide Web Consortium (W3C **) Web Content Accessibility Guidelines (WCAG) (3), require human judgment to evaluate. To accurately measure full compliance, human review of content is mandatory. For a large Web space, then, this task may not be feasible, and thus it seems impossible to determine the complete accessibility picture. One could randomly select a few sites for human review, but that would not provide a pan-enterprise perspective. The final section of this paper describes a new approach to this problem that leverages knowledge gained from an automated compliance system to build a statistical model of the Web space, allowing for the creation of an economically feasible sampling system and prediction algorithm that creates a total compliance picture even for a Web space that includes millions of documents.
DEVELOPING USABLE ACCESSIBLE SITES
A large number of processes affect the development and maintenance of accessible Web sites and applications. For example, authors and developers can be educated to create accessible content. Authoring, development, and host services packages affect how people with disabilities interact with sites. These topics are discussed on the IBM Accessibility Center Web site. (4) In this section, we focus on the development of site templates (such as those recently implemented in IBM) that have yielded phenomenal gains, not just in standards compliance, but in usability enhancements for people with disabilities. These gains came at little cost and are very popular with their target audience.
Many people have found the Web more useful as it grows more capable of information consolidation and personalization. However, the Web has become more confusing to people with disabilities. Web portals, which consolidate many information sources, are an example of one such simultaneous advance and step back. A portal page, with its multiple views into many different kinds of information, can be a boon to those who are able to visually scan it like a dashboard and almost instantly detect new information or points of interest. On the other hand, portals offer incomprehensible chaos to the visitor who is blind or visually impaired.
Satisfying the requirements described in accessibility standards is helpful; yet compliance with the standards is not enough to bring order to the chaos. The accessibility features described in this section make a complex page, such as a portal, extremely usable. Moreover, these features can be used to great benefit on any type of Web page.
Navigation challenges
Today's Web portal page is a multicolumn collection of small blocks or windows, each providing a view into a specific set of information. The computer applications that produce these windows are commonly called portlets. Each portlet collects and displays its information independent of others that may share space on the portal Web page.
As an example, we consider the needs of employees in a large enterprise with an abundance of information resources. The enterprise intranet portal serves a large employee audience and includes multiple portal pages, each with a collection of portlets. In its nonmodified form, the topmost portal page is the company's main bulletin board, which includes company news, stock market information, an enterprise directory, personal link lists, and search portlets. A second portal page includes portlets for work tools, such as asset and expense reporting, selling information, and personalized industry news. A third portal page concerns employees, with portlets for various human-resources and employee-benefit programs.
To add personalization, employees are given the ability to move portlets around in order to suit individual preferences. Any portlet can be moved to any portal page and positioned on that page as preferred. The result is a large collection of information sources and tools that employees add, delete, and rearrange to meet their own needs and goals. In essence, every employee has his own customized enterprise portal.
The challenge in adding accessibility to this portal is: How can a blind person gain a sense of, and remember, what and where all the pieces comprising the portal are?
Accessibility solutions
An initial accessibility accommodation for navigation in this portal consisted of a pair of "skip links" for each portlet, allowing the user to skip to the next portlet or the previous portlet. These generic aids might have met accessibility requirements, but they failed to go beyond compliance and added little to usability.
Gaining a sense of even a single portal page containing only a few portlets requires strong concentration; understanding it is difficult to achieve. For one blind employee, understanding the home page took many visits and, finally, some explanation from a sighted colleague. In order to improve understanding, the templates used to create portal pages were enhanced with the following methods: structured HTML, landmarks, a page index that accurately described the page, access keys, and provisions for personalized page styling. Each of these techniques (described in the following sections) is embedded directly into the templates, making it easier for portlet developers and content producers to keep new pages accessible. An additional benefit of this approach is that developers no longer need to remember to include obscure or infrequently used features.
Structured HTML
HTML coding techniques were changed to use a semantically correct structure: that is, headings, paragraphs, and lists. The previous technique used HTML spans to apply a Cascading Style Sheet (CSS) appearance to a line of text, making the text appear like a heading. Spans were eliminated in favor of true heading markup. These techniques are illustrated in Table 1. This change alone had immediate beneficial impact because assistive tools known as screen readers have facilities that take advantage of good structure. For example, a simple screen reader command can quickly invoke the reading of all headings on a Web page, giving a blind visitor an outline of the important information on the page.
Hiding accessibility information
Part of the portal design update consisted of moving from a layout technique that depended on tables and "spacer" images to one that used CSS technology for positioning. Because this new approach used no spacer images, the traditional method of attaching a skip link to a spacer image needed reconsideration. A CSS technique was developed that replaced the spacer image technique. The technique "parks" accessibility information in an imaginary space far to the left of what a visual Web browser is capable of displaying. While screen readers can find this information, Web browsers do not. This new method (called "access") was tested with a wide range of screen readers and is now used for more than just skip links. (5) See Table 2 for examples of making accessibility information invisible to the user.
Landmarks: What part of the page am I listening to now?
Imagine a shopper not knowing whether he or she is standing in a shoe stare or a bookstore. This is similar to the experience of trying to understand a portal page with portlets when using a screen reader. Knowing which section of the page currently contains the focus is crucial to understanding the content presented at that time; that is, the context in...
NOTE: All illustrations and photos
have been removed from this article.
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