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Re: Level AA exceptions

From: Phill Jenkins <pjenkins@us.ibm.com>
Date: Fri, 14 Aug 2015 14:25:06 -0500
To: Gregg Vanderheiden <gregg@raisingthefloor.org>
Cc: GLWAI Guidelines WG org <w3c-wai-gl@w3.org>, IG - WAI Interest Group List list <w3c-wai-ig@w3.org>
Message-ID: <OF2E65CB3B.BEC51078-ON86257EA1.0062E9F2-86257EA1.006AAD1E@us.ibm.com>

> Hope this helps

Sure, but mostly what I already posted.  What's missing is the documented 
rationale for why an individual particular SC is considered Level AA.  We 
have all the "possible" factors, being 'Essential" was indeed one of the 
factors, But we don't have documented which of the many possible factors 
were considered for this particular SC. Yes we know in general that all 
these factors may have been considered for all the SC.  but, For example, 
        Why was SC 1.4.3 Contrast Minimum assigned AA? 
        Why was SC 2.4.7 Focus Visible assigned AA? 
Many feel it is essential, but mostly handled by the browser, is that why? 
 where is that written? 

Why a SC is assigned Level AAA seems to be more clear and agreed to 
because it was not possible to meet them for all web sites and types of 

Are there other factors that were considered that weren't listed, such as 
availability of assistive technology in certain languages or countries? 
The availability of certain assistive technology features that are now in 
browsers is another factor not explicitly listed.  For example, Apple iOS 
has a newer contrast and font feature, does that have a factor in 
considering why SC 1.4.3 Contrast Minimum is assigned Level AA?  In other 
words, when should a new success criteria replace the existing one? Should 
the new one place the requirement that the web content should not 
interfere and should respect the contrast settings of the platform, 
similar to the way the SC 1.4.4 Resize Text is Level AA?

Again, is having a synopsis of the rationale for why each individual 
particular SC was assigned Level AA of value to everyone on this list? 
Phill Jenkins, 

From:   Gregg Vanderheiden <gregg@raisingthefloor.org>
To:     Phill Jenkins/Austin/IBM@IBMUS
Cc:     IG - WAI Interest Group List list <w3c-wai-ig@w3.org>, GLWAI 
Guidelines WG org <w3c-wai-gl@w3.org>
Date:   08/13/2015 11:20 PM
Subject:        Re: Level AA exceptions

Hi Phil

Being Essential was indeed one of the factors. 
However essential was not the dividing line between A and AA.   There are 
AA level provisions that are essential as well.    In fact there are AAA 
level provisions that are essential but that are in Level AAA because it 
was not possible to meet them for all web sites and types of content that 
the SC would apply.   So Essential is not a criteria by itself for an SC 
being in any level.    None of the items in the list was determinant for 
level A or AA provisions. 

How were the levels decided for each SC? 
As the Understanding WCAG 2.0 doc says - it was based on many factors - 
some of which are listed below. 

All of these factors in the list were considered by the working group in 
deciding which level something went into.  There was never one factor. And 
there is no formula.  The level the SC ended up in was the level that the 
group reached consensus on for that provision -  given the different 
considerations below and more.  The list below are the ones identified in 
asking the group what was considered.    But it is not likely that is is 

So the answer to  ?why was a particular SC placed in level A or AA or 
AAA??  is: 
  Because it was the consensus of the Working Group that it be placed 
And the answer to  ?Bhat did they consider in placing the provision 
there??  is: 
The list in Understanding WCAG 2.0 gives the major considerations we 
identified but there are likely others as well. These are the ones the 
working group identified in answering this question. 

So what is the difference between A  and AA and AAA.  Think of them as a 
measure of accessibility as in    1 inch  2 inches and 3 inches.   each 
one is longer than the one  before.     A is so accessible. AA is more 
accessible and AAA is still more accessible.       People can decide how 
long (inches ) is long enough for a nail for example in order to hold up a 
beam.     Or how accessible something has to be in order to meet a minimum 
accessible standard.      Most have decided that A was not enough and that 
AA should be required by looking at what was in A and AA.    The working 
group recommended against requiring AAA for all content because there are 
some provisions there than cannot be applied to all content.  And there 
are other factors for others that put them in this category.   But there 
are places that require AAA for some parts of a site - or for some types 
of content - where they could apply there.   And there are those who reach 
AAA because they can for their site and they want to go further than Level 

Hope this helps.

(PS this is from my personal knowledge and memory of the working group and 
the proceedings - and is not an official statement of the working group) 
(PPS  the PS  is my standard disclaimer for anything that is from my 
recollection and understanding and not reviewed and vetted by the working 
group current and past).


Gregg Vanderheiden

On Aug 13, 2015, at 7:41 PM, Phill Jenkins <pjenkins@us.ibm.com> wrote:

As more and more policies and regulations adopt both level A and AA and 
thereby place more of the responsibility and burden on the web content, 
the notion of the difference between and rationale for having Level A and 
AA is getting lost and misunderstood.   

Is there still general consensus that there are interacting issue that 
need to be considered when applying Level AA Success Criteria to all web 
content and web applications?   

See Understanding Levels of Conformance 
"The Success Criteria were assigned to one of the three levels of 
conformance by the working group after taking into consideration a wide 
range of interacting issues. Some of the common factors evaluated when 
setting the level included: 
whether the Success Criterion is essential (in other words, if the Success 
Criterion isn't met, then even assistive technology can't make content 
whether it is possible to satisfy the Success Criterion for all Web sites 
and types of content that the Success Criteria would apply to (e.g., 
different topics, types of content, types of Web technology) 
whether the Success Criterion requires skills that could reasonably be 
achieved by the content creators (that is, the knowledge and skill to meet 
the Success Criteria could be acquired in a week's training or less) 
whether the Success Criterion would impose limits on the "look & feel" 
and/or function of the Web page. (limits on function, presentation, 
freedom of expression, design or aesthetic that the Success Criteria might 
place on authors) 
whether there are no workarounds if the Success Criterion is not met."

So, that says to me that Level AA Success Criteria are not "essential", 
some may not always apply to all types of content (e.g. contrast on 
complex visualizations), some may require skills that cannot always be 
reasonably achieved by the content creators (e.g. video descriptions), and 
that it may impose limits on the "look & feel" and/or function (e.g. more 
images / less text), although I believe those success criteria imposing 
limits were identified as Level AAA. 

In other words "...you are advocating that AA success criteria should have 
more 'wiggle room' than Level A Success Criteria" ? 
Yes, because the working group reached consensus on making it level AA 
instead of Level A because of the wide range of interacting issues. 
However, none of the supporting documents (Note1) have listed the specific 
"interacting issues" per individual success criteria for why it was 
assigned level AA or level AAA instead of level A.  Yes there are 
exceptions listed where appropriate for both Level A and AA Success 
Criteria, but those are not the all the issues discussed that caused the 
criteria to be assigned as AA instead of A.  Most if not all the 
"interacting issues" are logged deep in the e-mail archives of the working 

So, should there be documentation added on the rationale for why a success 
criteria was assigned level AA (instead of A or AAA) to help practitioners 
better understand "how to apply level AA success criteria" as compared to 
applying Level A success criteria?   For example, should a non-normative 
section be added titled  "Rationale for assigning this SC to Level AA" be 
added  to the Understanding WCAG 2.0 guide? 

Note 1: Supporting documents: 
1. Understanding WCAG 2.0 
2. How to Meet WCAG 2.0 http://www.w3.org/WAI/WCAG20/quickref/ 
Phill Jenkins, 
Received on Friday, 14 August 2015 19:25:42 UTC

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