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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]

From: Michael Cooper <cooper@w3.org>
Date: Wed, 27 Nov 2013 15:03:22 -0500
Message-ID: <5296500A.3060609@w3.org>
To: David MacDonald <david100@sympatico.ca>, 'Janina Sajka' <janina@rednote.net>, 'HTML Accessibility Task Force' <public-html-a11y@w3.org>, WCAG WG <w3c-wai-gl@w3.org>, public-comments-wcag20@w3.org
CC: 'Gregg Vanderheiden' <gv@trace.wisc.edu>, kirsten@can-adapt.com
I thought it would be helpful to clarify what the WCAG Working Group is
considering and its reasons for asking the question that started this
thread.

To recap background on the structure of WCAG 2.0 and its supporting
materials: The Web Content Accessibility Guidelines 2.0 defines
normative requirements for accessible content. This means that an author
wishing to claim conformance to WCAG 2.0 must ensure their content meets
the Success Criteria. The WCAG 2.0 Success Criteria are abstract,
though, so they are supported by informative resources including the
WCAG 2.0 Techniques. Informative resources provide interpretive guidance
from the WCAG Working Group, and Techniques suggest how the Success
Criteria might be met in particular technologies. But these are only
informative suggestions, and it is possible to meet or fail to meet the
Success Criteria without matching the patterns suggested in the techniques.

The same is true of Failure Techniques. These describe authoring
practices that might cause a page to fail the Success Criteria. But
these, too, are informative, and it is possible to fail the Success
Criteria in other ways, or to use patterns that match a failure
technique but do not in fact cause the page to fail because another
technique was used that caused the page to pass. In fact, as time
passes, the Working Group has become more and more concerned that some
of the failure techniques no longer describe situations that always
fail, due to changes in technology. The group is now trying to identify
and update some of these techniques.

This brings me to the technique at question in this thread, "F65:
Failure of Success Criterion 1.1.1 due to omitting the alt
attribute...". This technique says it is a failure of WCAG 2.0 if the
alt attribute is omitted on certain elements, because text alternatives
would not be available. Since the time that technique was written, new
approaches to associating text alternatives have become available, for
instance aria-label and aria-labelledby among others. While there are
concerns about how widely implemented these are and if they fully
fulfill the role of alt, it seemed to the Working Group that it would be
worth updating the failure to reflect new technology, so it would not
indicate that content fails when it may not.

There are many considerations to making a change like this. Although
failure techniques are only informative, the goal is to make them as
accurate as possible to the technologies of the time. But as we all
know, there is not consensus in the accessibility community about
whether newer technologies are an acceptable replacement for alt, for
both technical and strategic reasons. The WCAG WG did not want to make a
change to the technique that is not in line with the consensus of the
HTML Accessibility Task Force which has worked most closely within W3C
on this issue. This is the reason that the group brought the question to
this forum.

The purpose of all this background is to clarify the intentions and
plans of the WCAG Working Group. The goal is to coordinate and make sure
the group takes an action that is accepted in the accessibility
community, rather than make one decision within the WCAG Working Group
that it knows might not be accepted by many other stakeholders. The
group wants to understand the variety of perspectives and does not
intend to make a hasty or one-sided change. It seems, though that some
update to the failure technique is needed, although it could turn out
after this exploration that the consensus is not to change the
technique. Even after the group makes a proposed change, if any, to the
technique, there will be further rounds of review - in context of a
draft of the technique at that point. And in the end, the technique is
still non-normative - other organizations are free to disagree with it
and follow other approaches to meet WCAG 2.0.

I hope this helps people understand the intent of the message that
started this thread and what the WCAG Working Group does and does not
plan to do.

Michael
On 22/11/2013 6:27 PM, David MacDonald wrote:
> On behalf of the WCAG working group, I have an action item to solicit
> responses from the wider community regarding a proposed amendment to WCAG
> failure technique F65 regarding missing ALT. Currently; if an <img> element
> is missing from an ALT attribute the page fails WCAG SC 1.1.1 Level A. Some
> are proposing that we allow authors to use the aria-label, aria-labelledby,
> and title attributes INSTEAD of ALT. 
>
> So under the amended failure technique NONE of the following would fail
> WCAG:
>
> <img src="../images/giraffe.jpg" title="Giraffe grazing on tree branches"/>
>
> <img src="../images/giraffe.jpg" aria-label="Giraffe grazing on tree
> branches"/>
>
> <img src="../images/giraffe.jpg" aria-labelledby="123"/>
> <p id="123"> Giraffe grazing on tree branches</p>
>
> As you can imagine there are strong opinions all around on this so I
> suggested we get a sense of what other groups such as the HTML5 A11y TF and
> PF think.
>
> Those in favour of the change provide the following rational: 
>
> --These alternatives on the img element work in assistive technology
> --The aria spec says these attributes should get an accessible NAME in the
> API  
> http://www.w3.org/TR/wai-aria/roles#textalternativecomputation 
> --They say it's easy to teach beginner programmers to just always use an
> aria label on everything, rather than requiring a label on form fields and
> alt on images
> --They feel as a failure F65 is very strong if fails a page for missing ALT,
> especially if other things work, and they would like to soften it to allow
> other things that work.
> --html 5 allows a <figure><legend> combination instead of alt, so they feel
> WCAG will have to change F65 anyway to allow a figure with a legend, and
> that helps open the door to this discussion
>
> Those in favour of the status quo (which fails missing alt text) provide the
> following rational:
>
> --aria-label, labelledby and title, are not really suitable attributes for
> img alternative text because they implies a label or title, rather than an
> alternate text, so it is not a semantic equivalent
> --title is not well supported
> --some feel that the aria spec is not in any way suggesting these as
> replacements to ALT.
> --aria instructs authors to use native html where possible, and they could
> not come up with viable use cases of omitting alt text
> --there are hundreds of millions of dollars invested in current evaluation
> tools, and methodologies, and this would represent a major departure from
> one of the most basic accessibility convention, that is almost as old as the
> web and is the "rock star" of accessibility
> --it could cost a lot of money to change guidance to developers etc..., and
> muddy the waters on a very efficient current evaluation mechanism
> --when the figure/legend is supported by AT we can amend F65 but that is a
> different issue and the semantics of this construct are OK for text
> alternatives, rather than the label/labelledby/title options
> --it may cause some confidence problems to WCAG legislation, because it
> represents a strong loosening to a fundamental Success Criteria, an
> unnecessary change that doesn't help the cause of accessibility, but just
> complicates things
> --ALT is better supported and the text appears when images are turned off.
> --initial twitter feedback from the community is strongly against changing
> this failure
>
>
> There are probably other reasons on both sides which we hope to hear ... but
> these should start it off. Please give your opinions and reasons.
>  
> Current technique here:
> http://www.w3.org/TR/WCAG-TECHS/F65.html 
> Proposed failure here (see test procedure)
>
>
>
> Cheers,
> David MacDonald
>
> CanAdapt Solutions Inc.
> Tel:  613.235.4902
> http://ca.linkedin.com/in/davidmacdonald100
> www.Can-Adapt.com
>    
>   Adapting the web to all users
>             Including those with disabilities
>
>
>
>

-- 

Michael Cooper
Web Accessibility Specialist
World Wide Web Consortium, Web Accessibility Initiative
E-mail cooper@w3.org <mailto:cooper@w3.org>
Information Page <http://www.w3.org/People/cooper/>
Received on Wednesday, 27 November 2013 20:03:44 UTC

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