Re: Estimates of Accessible Web Sites

Your numbers sound reasonable to me.

Charles Munat
Seattle, Washington

Kynn Bartlett wrote:
> Hi everyone,
> 
> I recently got email which asked me:
> 
>> Just wondering if you folks had any estimates of what percentage of 
>> websites are now accessible.  I know Kynn Bartlett has this info.  
>> Thank you for any information.
> 
> 
> Unfortunately there are no strict figures on this for several reasons:
> 
> (1) The term "accessible" is not an absolute; a site may be accessible to
>     to one person with one set of abilities and not accessible to someone
>     else.  Lack of alt attributes on an image may not bother a deaf user,
>     and lack of transcripts and captions for multimedia may not affect a
>     dexterity-impaired user.
> 
> (2) A site with accessibility problems could range from "difficult to use"
>     to "impossible to use" in various sections and for different users,
>     making it hard to arrive at a definition of "accessible" that covers
>     a site.  For example, if there is a single image missing an alt 
> attribute
>     on a single page on the site, is that site accessible or inaccessible?
> 
> (3) There are several standards for measuring accessibility, including the
>     U.S. government's Section 508, the W3C's WCAG 1.0 in levels A, AA,
>     and AAA, "Bobby compliance", and several others.
> 
> (4) There is no automatic way to check for accessibility or even for
>     compliance with accessibility standards, because property evaluating
>     accessibility compliance (e.g. "is this alt text a proper alternative
>     for this image?") requires human judgment.
> 
> (5) There are no reliable methods for taking a sample of sites and
>     checking the accessibility of those sites, and extrapolating to the
>     rest of the Internet.
> 
> This doesn't make it impossible to estimate, but such estimations depend
> on who exactly you ask and what assumptions they make to formulate their
> answers.
> 
> Here are my estimates:
> 
> 95%+ of Web sites have minor accessibility errors which will make them
>      annoying to use for at least one identifiable user group.
> 
> 75% of Web sites have moderate accessibility errors which
>     will make them difficult to use for at least one identifiable
>     user group.
> 
> 50% of Web sites have serious accessibility errors which will make them
>     almost impossible to use for at least one identifiable user group.
> 
> 25% of Web sites have catastrophic accessibility errors which make them
>     unusable by at least one identifiable user group.
> 
> Where did I get those figures from?  I made them up, based on my
> knowledge of Web design and accessibility techniques.  I would say this
> is an improvement over 4 years ago, when the numbers would have been:
> 
> 99%+    Minor accessibility errors;
> 90%     Moderate accessibility errors;
> 75%     Serious accessibility errors;
> 50%     Catastrophic accessibility errors.
> 
> What do you all think?  What categories would you use and what percentages
> would you set?
> 
> --Kynn
> 
> -- 
> Kynn Bartlett <kynn(at)idyllmtn.com>                http://kynn.com
> Chief Technologist, Idyll Mountain           http://idyllmtn.com
> Author, CSS in 24 Hours                  http://cssin24hours.com
> 
> 

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