XHTML: Accessibility Tips
The library is committed to serving the entire public, and that means striving to ensure that all pages of our site are accessible to the greatest possible number of people and devices (including audio browsers, Braille readers, and other specialized browsing environments).
In addition, accessibility is now U.S. law for all government and publicly funded sites.
Education and Compliance
The following links can help you develop pages that comply with accessibility laws and guidelines:
- WAI Accessibility Guidelines
- These guidelines offer compliance tips, and outline various levels of compliance.
- Bobby Accessibility Validator
- The Center for Applied Special Technology has created this online tool that analyzes web page accessibility based on the W3C guidelines.
Accessibility and Web Standards
In a perfect world, the library’s website would be authored in XHTML 1.0 Strict, using absolutely no deprecated HTML “design” elements. Visual design would be handled via Cascading Style Sheets exclusively.
This strict separation of structure (XHTML) from style (CSS) would enable us to comply with the W3C's Priority One rating for User Agent Accessibility Guidelines 1.0, and would also vastly simplify the design, development, and maintenance of our site.
With such an approach, our site could look great in a standards–compliant browser, and yet remain accessible to virtually any known browser or Internet device.
The Bad News
Unfortunately, many web browsers used by our audience are not sufficiently CSS-compliant - over one third still use some version of Netscape 4.x. Happily, NYPL has upgraded our onsite PCs to Internet Explorer 5.5.
The Transitional Solution
In order to design sites that achieve at least a minimum of accessibility and that work well in Netscape 4, our pages must:
- Meet the XHTML 1.0 Transitional standard, including the DOCTYPE and XML namespace declaration described on our XHTML Guidelines page.
- Provide text equivalents for all non-text elements (i.e., images, animations, audio, video).
- Provide summaries of graphs and charts.
- Ensure that all information conveyed with color is also available without color.
- Clearly identify changes in the natural language of a document's text and any text equivalents (e.g., captions) of non-text content.
- Structure content logically and clearly.
- Provide alternative content for features (e.g., applets or plug-ins) that may not be supported.
- Ensure that tables are constructed so that a user accessing the site with a screen reader or other assistive technology is presented with content in a logical order.
- Ensure that tabbing order flows logically. That is to say that if a user is tabbing rather than clicking through our site, her progress through the site is logical.
- Ensure that forms tab logically.
- Avoid invisible spacer GIFs and similar visual junk.
- Use tables for layout sparingly. (And if possible, avoid using HTML tables as design tools altogether. For instance, this page uses no HTML tables, and it works in Netscape 4.7, although the layout is necessarily somewhat degraded in that browser.)
In addition, all XHTML and Style Sheets must validate, a simple process described on the very next page. »
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