WCAG 2.0 Conformance Model

We don't currently have any open issues about it (they were closed at 
Seattle).  But for your interest and our archives here is an explanation of 
the WCAG 2.0 Conformance Model, as well as its rationale, from WCAG WG 
co-chair Gregg Vanderheiden...

>[...]
>At 03:48 PM 2/4/03 -0600, Gregg Vanderheiden wrote:
>
>=====================================
>
>HI Lofton
>
>Our old model (in WCAG 1.0) was cleaner to explain - but only as long as 
>you didn t really look closely.  Then it was inaccurate and 
>misleading.  It wasn t intended to be but we found it was as we explored 
>it more deeply during our look at WCAG 2.0
>
>On the surface,  A items were the only ones that prevented people from 
>using the web
>AA were needed or it was hard for some and Doing AAA made it easier still
>
>In reality,  some people couldn t use the web unless you did items in AA 
>or AAA.   What made things easier for some -- made it possible at all for 
>others.
>
>ALSO, there were some things that weren t in A because they couldn t be 
>done on all sites -- not because they weren t needed.
>
>We also found that there were important topics that didn t get looked at 
>if they didn t fall into A.
>
>
>So for WCAG 2.0 we have the 4 major areas that comprise access with 
>checkpoints for each.   Under each checkpoint we have 3 levels of success 
>criteria.    There is nothing in the levels that is not testable.  If 
>people are going to claim conformance, it has to at least be possible for 
>them to determine themselves if they have done it.  Or what "it" is.
>
>Level 1 or the MINIMUM level is what we think is the absolute minimum that 
>someone has to do in order to say they conform to the guidelines.   Level 
>2 is for people who want to or are asked to do more.   And level 3 is for 
>those who want to really go all out.   In addition, we have advice on 
>things to work toward or keep in mind that are not testable.
>
>We don t make judgments now about whether people can or can t use a 
>site.   If you do level 1 - it addresses the most important items that can 
>be applied generally across sites.    Level 2 makes it easier for some and 
>possible for others (that can t use it without the level 2 items.)  Ditto 
>for Level 3.
>
>Below is the latest text for description of the Levels.  This is rough and 
>not final.  We are still working on the items for each level and final 
>definition of the levels.
>
>Also note that we allow people to report level 1+ or level 2+ if they 
>complete 1 plus some extra points.  We are still discussing whether and 
>how they would have to report which items beyond a level that have been 
>conformed with.  EARL is one key approach being explored but not required.
>
>Does this help better understand the change?  And rationale?
>
>Oh yes, and as for the plenary, while discussion of conformance-related 
>issues at the technical plenary is certainly possible, the meeting at the 
>plenary is intended to discuss WCAG 2.0 authoring techniques rather than 
>the guidelines and conformance requirements.    Issues regarding the 
>conformance approach will be taken up at a second meeting, later in March, 
>to be held in conjunction with the CSUN conference. It might also be 
>desirable to set up a joint teleconference to discuss any 
>conformance-related issues that need to be addressed either before or 
>after that meeting.
>
>Take care and let us know if this is not clear or we can provide any 
>additional info.
>
>And remember that this is still a work in progress so all of this might 
>shift as we go forward. This is just a snapshot of where we are.
>
>Comments welcome.
>
>Gregg for the WCAG team
>
>  -- ------------------------------
>Gregg C Vanderheiden Ph.D.
>Professor - Ind. Engr. & BioMed Engr.
>Director - Trace R & D Center
>University of Wisconsin-Madison
>
>
>Conformance
>
>
>
>WCAG 2.0 provides three levels of conformance for each of its 21 
>checkpoints.
>
>MINIMUM LEVEL. includes success criteria for the checkpoint that address 
>key problems and are applicable across the broad range of Web content and 
>sites.  Conformance at this level will substantially overcome the barriers 
>for many people with disabilities, but there will be people with 
>disabilities who will still not be able to access the content.  No claim 
>of conformance can be made unless the minimum level of conformance is 
>achieved for all checkpoints.
>
>LEVEL 2 includes additional success criteria that increase the 
>accessibility of Web content, but that are more difficult to implement on 
>Web content in general or on specific types of content.
>
>LEVEL 3 represents the highest level of conformance in WCAG 2.0.   It 
>includes success criteria that may be very difficult as well as criteria 
>that may not be possible at all for some types of content or some Web 
>architectures.
>
>
>
>==========================================================
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>-----Original Message-----
>
>From: Lofton Henderson [mailto:lofton@rockynet.com]
>
>Sent: Sunday, February 02, 2003 1:58 PM
>
>To: jasonw@ariel.ucs.unimelb.EDU.AU; gv@trace.wisc.edu
>
>Cc: chisholm@w3.org
>
>Subject: Observe at Boston?
>
>
>
>Dear Jason, Gregg --
>
>
>
>At the Boston tech plenary week, we QA people will be doing some outreach
>
>and will be visiting a few of the Working Groups on Mon-Tues.
>
>Our objectives are to introduce ourselves to the WGs (not that QAWG and
>
>WCAG need introduction!), learn more about what you are doing (**), and
>
>provide any assistance we can with respect to QA.  Would be okay for me to
>
>attend WCAG as an observer, for part of your meeting?
>
>
>
>(** We notice that WCAG 2.0 introduces changes to the Priority-based
>
>checkpoint conformance model.  QAWG has looked at this a bit, since we
>
>based our Guideline/Checkpoint model on WAI's.  Preliminary conclusion is
>
>that the older model fits our usage scenarios better, but I'm interested to
>
>learn more. )
>
>
>
>Additionally, you or members of WCAG are welcome to join us on Thursday and
>
>Friday for our meeting (but please let us know soon, for room-size
>
>planning).  Note that we already have some joint meeting time and a topic
>
>list with UAWG, and I notice that Wendy is registered as an observer.
>
>
>
>What I would anticipate is to sit in for 1/2 day at least.  If you had test
>
>suite, conformance, or other QA topics on the agenda, that would probably
>
>be the most interesting time to visit.  I'm also keenly interested in your
>
>approach to outreach (Quick Tips, etc), which Wendy previewed for us a
>
>little bit at our recent Seattle f2f meeting.
>
>
>
>In addition, perhaps I can provide useful information.  We (will) have a
>
>briefing package/kit about what we're doing.  I'd also be happy to answer
>
>questions, hear your thoughts about QA's direction and
>
>activities.  Finally, three of the QA Framework guidelines documents will
>
>be in Last Call then, and we could talk about that, if WCAG members had
>
>interest or questions.
>
>
>
>Please let me know which 1/2 day (at least) would work best for you.
>
>
>
>Best Regards,
>
>-Lofton Henderson
>
>QAWG co-chair
>
>
>
>
>
>