Webserver use, configuration and management Unit WUCM1

Validating a web site

Validation for conformance to HTML standards

The basic task for this tutorial is to explore the services provided by some of the different online validation services.  

The first one to consider is the World Wide Web Consortium's HTML Validation Service. This may be found at http://validator.w3.org/. Hopefully you have come equipped with a suitable URL that you want to validate, if not then try some of the University pages. The W3C validation service invites you to fill in the URL and submit the form. There are a number of options, try different combinations.

The trick now is to try and make sense of the conformance issues the validator raises. Do have a look at the other facilities after you have sorted out the validation report.

Why is it important to validate your website in this way? In almost all cases, the author of the page you have examined would have checked with their web browser, and presumably been satisfied that it displayed in a suitable form. If they were conscientious and had time they might have checked it with a number of browsers. Try to list out as many reasons as you can think of for why the page is not 'clean'. (In the rare instance that you have picked a clean page, try one of mine!)

Validation for accessibility

In this context we are evaluating the page with a view to seeing how useful it might be to a person with disabilities. The validation may consider:

• the World Wide Web Consortium's (W3C) Web Content Accessibility Guidelines, see http://www.w3.org/WAI/GL/ or
• legal implications, as both in the USA (Section 508) or the UK (the SENDA legislation) have come into effect.  

Much of the original work on accessibility was done by CAST with their Bobby tool. Bobby's analysis of accessibility is based on the World Wide Web Consortium's (W3C) Web Content Accessibility Guidelines. For example, to become Bobby approved, a website must:

• 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 colour is also available without colour
• Clearly identify changes in the natural language of a document's text and any text equivalents (e.g., captions) of non-text content
• Organise content logically and clearly
• Provide alternative content for features (e.g., applets or plug-ins) that may not be supported

Unfortunately, Bobby is no longer freely available (it is now part of IBM Rational Policy Tester Accessibility Edition software).

Tools

Two lists of available testing tools can be found at:

• http://www.w3.org/WAI/ER/tools/
• http://www.htmlhelp.com/

Try out at least one of these tools on some web pages of your own.

A search on your favourite search engine for "HTML Validators",  "Link Checkers", "LinkBots", or "Network Spiders" might be illuminating.

References

None specifically referred to, all on the web!