RE: Clarification of WCAG intent and meaning of techniques [Re: WCAG considering amending F65 to NOT fail missing ALT text if title or aria-label is present]

Schnabel, Stefan, Thu, 28 Nov 2013 13:09:21 +0000:
> Redundant announcement of accessibility related info by AT using 
> heuristics is not concept issue but an AT implementation flaw.

In this context, the point is to come up with uses cases for saying 
that one could just omit the @alt attribute if one includes the (right) 
ARIA attributes "instead". And if the only problem is the redundant 
announcement problem, then ARIA *can* solve that problem. (But, of 
course, may be AT could - via heuristics - solve it too.)

  …
> Supporting an empty alt will ease the pain but this renders the 
> Giraffe to "decorative" (unfortunately).

The reason it doesn't work is that it results in the same redundant 
announcement that we are trying to avoid. If an img with empty @alt has 
an aria attribute, then AT will not treat it as decorative. But, of 
course, someone with images disabled will not get any alt text for the 
image - for them it would probably be better with a dummy (alt) text of 
some sort. And this is also the reason why it, in such a case, might be 
better with an omitted @alt than an empty @alt.

> Using aria-hidden is not 
> reflecting well the purpose of the technique "association of visible 
> text (used as caption for an image) with the image".

This is true. The only *simple* method HTML5 seems to have for such 
association, is the <figure> element.

Leif Halvard Silli


> From: Steve Faulkner [mailto:faulkner.steve@gmail.com]
> Sent: Donnerstag, 28. November 2013 13:51
> To: Schnabel, Stefan
> Cc: Leif Halvard Silli; Michael Cooper; David MacDonald; Janina 
> Sajka; HTML Accessibility Task Force; WCAG WG; 
> public-comments-wcag20@w3.org; Gregg Vanderheiden; 
> kirsten@can-adapt.com
> Subject: Re: Clarification of WCAG intent and meaning of techniques 
> [Re: WCAG considering amending F65 to NOT fail missing ALT text if 
> title or aria-label is present]
> 
> Hi stefan, issue with this is
> SR output: graphic Giraffe grazing on tree branches ... Giraffe 
> grazing on tree branches
> 
> --
> 
> Regards
> 
> SteveF
> HTML 5.1<http://www.w3.org/html/wg/drafts/html/master/>
> 
> On 28 November 2013 12:48, Schnabel, Stefan 
> <stefan.schnabel@sap.com<mailto:stefan.schnabel@sap.com>> wrote:
>>> So, to replace @alt with an @aria-* attribute, would be to do the
> opposite of what the WCAG Robustness principle requires
> No.
> 
> <img src="../images/giraffe.jpg" aria-labelledby="123"/>
> <p id="123">Giraffe grazing on tree branches</p>
> is equivalent since even if the image is missing the text describing 
> the image is still there.
> 
> - Stefan
> 
> 
> -----Original Message-----
> From: Leif Halvard Silli 
> [mailto:xn--mlform-iua@målform.no<mailto:xn--mlform-iua@m%C3%A5lform.no>]
> Sent: Donnerstag, 28. November 2013 13:31
> To: Steve Faulkner
> Cc: Schnabel, Stefan; Michael Cooper; David MacDonald; Janina Sajka; 
> HTML Accessibility Task Force; WCAG WG; 
> public-comments-wcag20@w3.org<mailto:public-comments-wcag20@w3.org>; 
> Gregg Vanderheiden; 
> kirsten@can-adapt.com<mailto:kirsten@can-adapt.com>
> Subject: Re: Clarification of WCAG intent and meaning of techniques 
> [Re: WCAG considering amending F65 to NOT fail missing ALT text if 
> title or aria-label is present]
> 
> Steve Faulkner, Thu, 28 Nov 2013 10:24:29 +0000:
>> Hi Stefan, this only works for criteria that are solely contingent upon
>> accessibility APIs exposing information to AT.
>> 
>> For the case of alt it has not been agreed that this is the case.
>> 
>> Ramon, for example brought up the case of a low vision user who turns off
>> images in the browser because the information in the images is difficult to
>> perceive, but the alt text exposed as text by the browser is not. This
>> involves no AT.
>> 
>> In this case what is required for all of the suggested alternatives
>> aria-label etc is that they are displayed in place of an image when an
>> image is not displayed. This is currently not the case. If we can interest
>> browser implementers exposing aria-label as text in this case then we have
>> a practical alternative to alt.
> 
> So, to replace @alt with an @aria-* attribute, would be to do the
> opposite of what the WCAG Robustness principle requires:
> http://www.w3.org/TR/WCAG20/#robust

> 
> Leif H Silli
>

Received on Thursday, 28 November 2013 16:14:06 UTC