Bobby blows whistle on inaccessible Web pages

Bobby blows whistle on inaccessible Web pages

By Steve Graves

Special to GCN

Bobby 3.2, a free application from the Center for Applied Special Technology, analyzes Web page source code for accessibility to disabled users.

Section 508 of the Rehabilitation Act Amendments of 1998 requires federal Web developers to make their sites usable by the disabled. Although the White House has charged the General Services Administration with providing technical assistance on Section 508, no funds have been earmarked to help agencies comply.

All federal agencies must make their home pages and their 20 most frequently visited pages comply with Section 508. Government-sponsored trainers recently held three-hour Web accessibility workshops to encourage federal developers to check their sites with screen readers and other tools used by the disabled, but they could give no advice about how to pay for the necessary software and systems.

The cost of compliance testing is substantial. Professional-quality screen readers start at $500 to $600, and many packages cost $1,500 to $2,500'a large investment for agencies that employ dozens, sometimes even hundreds, of developers. Fortunately Bobby, one of the most useful tools, is free.


Bobby analyzed 20 government Web pages for Section 508 compliance in about an hour.


CAST, a not-for-profit organization, develops and distributes Bobby as a public service. Its corporate sponsors include HalfthePlanet.com of New York, IBM Corp., Microsoft Corp., Mitsubishi Electric America Foundation and Sun Microsystems Inc.

Bobby follows rules set by the World Wide Web Consortium's Web Accessibility Initiative, at www.w3.org/WAI, and a companion document, Web Content Accessibility Guidelines 1.0, at www.w3.org/TR/1999/WAI-WEBCONTENT-19990505.

The tool resembles a combination Hypertext Markup Language validator and Web spider. Like a validator, it examines and flags source code that doesn't meet accessibility guidelines. It's a spider in the sense that it can follow links to evaluate an entire site.

An online edition of Bobby hosted at the center's Web site, www.cast.org, functions like the locally installed version except that it can analyze only one page at a time. The center offers downloadable versions written in Java for Microsoft Windows 9x, Windows NT 4.0 and Windows 2000; Linux; SunSoft Solaris and other Unix flavors; Mac OS 7.6.1 and higher versions; IBM OS/2; BeOS; and other Java-capable platforms.

Easy to use

Security-conscious agencies that operate behind tight firewalls can get Bobby Server, although the Center for Applied Special Technology cautions that the server edition is still in testing and that agencies must provide their own technical support.

I found Bobby easy to install and use. It generated the first report within five minutes of downloading.

After installation, Bobby displays a three-step QuickStart guide. Comprehensive online documentation is available from the main screen. The help system, though somewhat disorganized, is objective and useful.

To analyze a site with Bobby, you enter a uniform resource locator and set the scope of the analysis from a simple drop-down menu. The default is to analyze a single page, but you can have Bobby follow all the links in the URL's domain, all the links in the URL's folder or all links on the Web site.

After Bobby finishes a run, it lists the URL on the main screen along with other completed accessibility analyses. You can see whether a page meets basic accessibility requirements, the number and classes of its priority errors, and the number of problems encountered for chosen browsers.

Bobby also produces a summary report and a detailed report for each site analyzed. The summary report lists all access issues found. Problems are grouped by page, priority, frequency and ease of fixing. The complete report gives detailed descriptions of the problems and suggestions for repair.

The Priority 1 accessibility section lists items that seriously affect use by people with disabilities. Pages that meet all Priority 1 requirements earn the consortium's WAI Conformance Level A rating.

Examples of Priority 1 requirements include alternative text for all images, applets and buttons; transcripts of all audio files; and synchronized text transcripts for video tracks. This aspect of Section 508 might discourage Web managers from broad use of bandwidth-hogging multimedia files.

Priority 2 accessibility problems are important but not vital. Many agencies require Web documents to meet Priority 1 as well as Priority 2 requirements; those that do are classified at Conformance Level AA under the WAI Web Content Guidelines.

Priority 2 requirements include descriptive titles for frames, limited use of pop-up windows, no blinking text and navigability without a mouse.

Priority 3, or third-tier access problems, involve items such as providing keyboard shortcuts for form elements, identifying the content language, and providing summaries and captions for tables. Sites that meet all three sets of requirements are classified at Conformance Level AAA under the WAI Web Content Guidelines.

Bobby's browser compatibility function flags HTML elements and attributes not valid for user-specified browsers. A page that is accessible to Microsoft Internet Explorer browsers might not be accessible to Netscape Navigator, or vice versa.

For this review, I used Bobby to analyze GSA's home page, as GSA is the agency responsible for educating the rest of the government about Section 508.

The home page at www.gsa.gov failed to win Bobby's approval because an image did not contain descriptive text'a Priority 1 requirement. The unlabeled image was simply a transparent spacer, but that is not a mitigating factor under Section 508. All images, including spacers, must have alternative text.

Bobby flagged www.gsa.gov for eight more page elements that require user checks, human judgments about their accessibility. For example, if an image conveys important information not communicated in the alternative text attribute, the developer must supply an extended description. Bobby cannot decide whether it is adequate. The same is true about the necessity of table headers and the use of color to convey information.






Box Score

Bobby 3.2

Section 508 site compliance tool


Center for the Applied Special

Technology; Peabody, Mass.;

tel. 978-531-8555 www.cast.org

Price: Free download form from dev.cast.org/bobby/download.cfm;
online version at www.cast.org/bobby;
call about operating Bobby Server behind a firewall



+ Price is right

+ Low system demands

- Doesn't check HTML syntax

- Limited ability to evaluate scripts, plug-ins and cascading style sheets

- Can't evaluate sites using Secure Sockets Layer or cookies


Real-life requirements:

Win9x, NT 4.0, Win 2000, Linux, Solaris, Mac OS 7.6.1 or higher, OS/2, BeOS or Java Virtual Machine 1.1.6 or higher; 2M of RAM; 5M of free storage for installation; at least 10M of scratch space for analysis




Bobby spotted three Priority 2 errors on the GSA home page and flagged 12 areas requiring manual intervention. The errors included using unfavored language, failing to separate links with more than white space and using absolute rather than relative positioning.

In addition, Bobby identified two Priority 3 errors with 14 user checks. It recorded seven compatibility errors for Netscape and Internet Explorer 4.x browsers.

Internet speed

Bobby works as fast as its Internet connection. I analyzed the home pages of 19 other federal Web sites in about an hour. Only the Interior Department's home page had no Priority 1 or 2 errors. In fact, the site was just one error away from earning a Conformance Level AAA rating.

In spite of its speed and convenience, Bobby has a long way to go to completely automate the analysis of Web sites, and its results must be used with caution. It conceivably could issue an approved rating for a site not in compliance if the developer failed to investigate the items that Bobby flags.

Bobby also sometimes fails sites that are fully accessible if it encounters an HTML syntax error. To avoid this, it's a good idea to run a conventional HTML validator first.

I found Bobby stable, with only one minor bug. The F1 key wouldn't open the Quick Tips file, and some users have complained they can't generate reports about large files.

Bobby's most glaring weakness is that it merely points out errors and lacks an integrated editor to repair them. The center has said Version 4.0 will include an editor with smart help to fix problems Bobby finds.

Even so, don't wait to grab this program. If you're responsible for a federal Web site's accessibility, Bobby is indispensable.

Steve Graves, a former GCN product reviewer, is publisher of Technical News Service Inc. of Cheverly, Md.

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