Re: Should validity be P1 or P2? (was RE: summary of resolutions from last 2 days)

This thread refers to "valid" code and I'm not sure everyone has the same 
definition.  In my mind valid HTML/XHTML code conforms to a DTD or schema 
- there are no errors when I test with a validity checker such as that 
provided by the W3C.  Well formed code will parse correctly but may not be 
valid.  It may have attributes specified for certain elements that are not 
part of the DTD.  The Level 1 SC addresses well-formed code but not 
necessarily valid code.  It is true that well formed code does not 
guarantee accessibility but it does help the assistive technologies to 
interpret the code. Yes, the user agents do a pretty good job of ignoring 
some set of coding errors and visually displaying the content but I 
believe the job is more difficult for assistive technologies. Thus, I can 
live with a requirement at level 1 that my code is well-formed - that is 
good coding practice and can help accessibility.   I can not live with a 
requirement for completely VALID code at level 1.

For example, The DHTML roadmap extensions that I and others are working on 
are meant to help accessibility. We are taking the paradigm of the client 
to the web by adding full keyboard support and the use of arrow keys to 
navigate rather than relying only on the tab key.   See 
http://www.mozilla.org/access/dhtml/ for more details on the Firefox 
solutions, we are working on IE compatible solutions.  Because the code 
relies on user agent extensions to allow the tabindex attribute on any 
element (and thus allow focus to that element), this code will not 
validate.  In the current HTML and XHTML DTDs, the tabindex attribute is 
specified only for the anchor and input elements.  If the requirement for 
valid code that conforms to a DTD is required at Level 1, I would not be 
able to use the DHTML roadmap to create a more accessible page!  We are 
working within the W3C to get this new technology fully supported in the 
specifications. But, that takes time and until that happens I could not 
conform to WCAG 2.0 if the validity requirement was at Level 1.   WCAG 2.0 
should not restrict projects that are working to improve accessibility by 
including Level 1 requirements that do not always guarantee accessibility. 
 

(Since I know some of you will object to the DHTML roadmap technologies I 
want to acknowledge that, Yes, the DHTML roadmap work does require 
JavaScript as part of the baseline technologies.  It may not be 
appropriate for all web sites but is certainly applicable in web 
applications where the audience and technologies in use are known). 


Becky Gibson
Web Accessibility Architect
                                                       
IBM Emerging Internet Technologies
5 Technology Park Drive
Westford, MA 01886
Voice: 978 399-6101; t/l 333-6101
Email: gibsonb@us.ibm.com