Re: A problem with some Web Accessibility Evaluation Tools

Hello,

Indeed, evaluating the non-rendered HTML will likely produce many false 
positives on most modern websites. We will consider your suggestion 
though this is not the only source for inaccuracy in evaluation tools, 
and we strongly recommend people to compare and understand the tools 
before using them. This is partially explained in this resource:
  - http://www.w3.org/WAI/eval/selectingtools

Regards,
   Shadi


On 22.9.2015 18:46, Hilera González José Ramón wrote:
> Dear all,
>
> Some of the tools included in the WAI Web Accessibility Evaluation Tools List (http://www.w3.org/WAI/ER/tools/), do not detect accessibility problems when a part of a web page is generated dynamically with JavaScript, as in this very basic example:
>
> <html lang="en">
>    <head>
>      <title>Page with image without text alternative</title>
>    </head>
>    <body>
>      <script language=javascript>
>         document.write("<img src=logo.jpg>");
>      </script>
>    </body>
> </html>
>
> If you test the above source code included in this web page: http://www.cc.uah.es/hilera/a11y/example.html
>
> You can see  that, at least, these online WCAG evaluation tools do not detect the non-compliance of Success Criterion 1.1.1 (Use alt on img elements):
>
>
> -        AChecker
>
> -        Examinator
>
> -        WAVE
>
> On the contrary, this WCAG evaluation tools can detect the problem:
>
>
> -        FAE
>
> -        Tenon
>
> -        Tingtun
>
> Probably, the problem arise because the first tools evaluate only the HTML source code, and the latter tools wait for JavaScript to render (JavaScript modifies the DOM), and then evaluate the HTML of the rendered page.
>
> So could be interesting to include an new filtering option in the WAI Web Accessibility Evaluation Tools List, as "Evaluation of DOM instead HTML source".
>
>
> Regards
>
>
> -------------------------------------------------------
> José R. Hilera
> University of Alcalá - Spain
> http://twitter.com/accesibilidad_w
>
>

-- 
Shadi Abou-Zahra - http://www.w3.org/People/shadi/
Activity Lead, WAI International Program Office
W3C Web Accessibility Initiative (WAI)

Received on Wednesday, 23 September 2015 14:31:37 UTC