encyclo - 1:32 am on May 6, 2007 (gmt 0)

The trouble with enforcing validity via the browser is that the end-user will download a new browser, try their favorite websites, see that those sites are broken, then blame the browser not the site, and revert back to what they were using before. And they would by quite right in their actions, as a browser's job is to display web pages, not to evangelize ideals. See the abject failure of XHTML to see the fallacy of the concept of the web with draconian error-handling.

Same goes for Google, unfortunately. If they were to promote accessibility by increasing ranking for accessible sites, their results would suffer as accessibility is not a criterion for relevance. Even if it were, there would be significant difficulties in algorithmically measuring accessibility, as the severe limitations of the current crop of accessibility validators show. Markup validity against a declared DTD is an extremely poor guide to accessibility when taken alone, so that would add no value to Google's algorithm either.

And if they did ever attempt something like this, who would be able to fix their sites in consequence? Those with the funds and the expertise to do so, like commercial entities, large companies, IT professionals. How would that "other" accessibility be affected - the accessibility which comes from the universality of the web, the low barriers to entry, the non-professional publishers, the personal pages...?

If Google is serious about web accessibility, it could always start by looking at its own coding practices and product sites before reaching out to push the concept on others.