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Re: Sufficient techniques- definition and guidance

From: Loretta Guarino Reid <lorettaguarino@google.com>
Date: Wed, 23 Mar 2011 09:22:12 -0700
Message-ID: <AANLkTimYDNzC_-JfCMLgoSVv0Pn8LTv8xHdHwO1mFAQo@mail.gmail.com>
To: Sailesh Panchang <spanchang02@yahoo.com>
Cc: w3c-wai-gl@w3.org, public-comments-wcag20@w3.org
On Thu, Feb 17, 2011 at 8:21 AM, Sailesh Panchang <spanchang02@yahoo.com>wrote:

> Loretta / Greg,
> Is this guidance contradictory and confusing?
>
> "How to meet WCAG 2.0" doc states:
> "Authors are encouraged to apply all techniques that they are able to,
> including the advisory techniques, in order to best address the needs of the
> widest possible range of users".
> On the other hand,  refer to "Sufficient and Advisory Techniques" under
>  Intro to Understanding WCAG 2.0, which states:
> "In order to provide guidance and examples for meeting the guidelines using
> specific technologies (for example HTML) the working group has identified
> sufficient techniques for each Success Criterion that are sufficient to meet
> that Success Criterion. Sufficient techniques are provided in a numbered
> list where each list item provides the technique or combination of
> techniques that can be used to meet the Success Criterion".
> "Most Success Criteria have multiple sufficient techniques listed. Any of
> the listed sufficient techniques can be used to meet the Success Criterion".
> So in the above, one doc says any one technique is sufficient and the other
> doc encourages  more than one technique to be implemented. So which is it. I
> do realize one uses "encourages". But:
> Specifically, consider SC 2.4.1 for skipping blocks of content:
> There are two groups of sufficient techniques: one for an actual skip nav
> link and the other set for proper structural markup like heading, frames,
> etc.
> One may conclude that if headings are implemented (H69) of group#2 of
> sufficient techniques, then SC 2.4.1 is met.
> But user agent notes for H69 acknowledge that this does not work in all
> situations. The actual skip nav link technique does work for a wider set of
> situations.
>  Then are individual techniques of the second group really sufficient?
> So while group# 2 of the sufficient techniques for SC 2.4.1 is helpful and
> enhances navigation abilities, they are not sufficient by themselves given
> today's user agent scenario.
> As for me, besides skip nav, I recommend headings and use of landmark roles
> too to clients.
> Please can you share your thoughts?
> Thanks,
> Sailesh Panchang
> www.deque.com
>
>
> ==============================
==
Response from the Working Group
================================
You seem to have interpreted it correctly.

- You CAN use just one of the techniques and you would meet the absolute
REQUIREMENTS for the success criterion.
- However, that is not all you can do in many situations.  There are other
things you can do beyond the minimum needed to pass the success criteria.
And we encourage people to go beyond the minimum.

As to part 2 of your question, if you know that a technique will not work,
then you should not use it.  However, there  are always grey areas where a
developer many not know if current user agents support something even though
many do or future ones would.  In this case the Working Group's decisions on
sufficiency can be helpful to the developer.   That is the case here.

In the end though, if you know that there are no AT that will work with the
described technique the way you are using it (or in the context you are
using it), then you should not use it because the accessibility support
requirement of the conformance requirements would not be met.


Loretta Guarino Reid, WCAG WG Co-Chair
Gregg Vanderheiden, WCAG WG Co-Chair
Michael Cooper, WCAG WG Staff Contact


On behalf of the WCAG Working Group
Received on Wednesday, 23 March 2011 16:22:44 GMT

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