Re: Example canvas element use - accessibility concerns

Rob Sayre wrote:
> [...]
> 
> <http://code.google.com/webstats/>
> 
> Is a good survey. Looks like there are a lot of alt attributes out 
> there. I wonder how many are empty, and how many are valid according to 
> the requirements in Hixie's draft (difficult to measure!)

 From a different data set (the pages from dmoz.org about a year ago) I 
got <http://philip.html5.org/data/alt-lengths.svg>, which shows 
something like 43% of image elements having empty alt text. 
http://lists.w3.org/Archives/Public/public-html/2008Apr/0536.html has 
some more details.

 From another different set (130K of the pages from dmoz.org about a 
month ago (which reflects changes in its list of pages, more than 
changes in the pages themselves)), 541634 out 1301287 image elements 
(42%) have empty alt text, so it seems fairly consistent.

(I've never actually looked at any of these images, so I don't know how 
many are valid.)

-- 
Philip Taylor
pjt47@cam.ac.uk