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Re: EvalTF discussion 5.5 and actual evaluation

From: RichardWarren <richard.warren@userite.com>
Date: Sat, 14 Jan 2012 01:32:56 -0000
Message-ID: <AC91D1382CD048468AAB86F218AB8038@DaddyPC>
To: "Eval TF" <public-wai-evaltf@w3.org>
Dear TF,

I cannot help thinking that we would save a lot of time and discussion if we concentrated on procedures for evaluation (5.3) where we are going to try “ to propose different ways to evaluate the guidelines: one by one, per theme, per technology, etc” .  As we do that we will come across the various technologies (5.2) and possibly come up with a few acceptable ways of dealing with “occasional errors” etc. if and when relevant to a particular guideline. This approach may be more efficient than trying to define systemic and incidental errors in a non-specific guideline context.

I wonder if now is the time to get to the core of our task and start working on actual procedures where we can discuss levels of compliance and any effect in a more narrow, targeted environment.


From: Elle 
Sent: Friday, January 13, 2012 11:35 PM
To: Vivienne CONWAY 
Cc: Alistair Garrison ; Shadi Abou-Zahra ; Eval TF ; Eric Velleman 
Subject: Re: EvalTF discussion 5.5


I have been reading the email discussions with avid interest and very little ability to add anything valuable yet.  My point of view seems to be very different from most in the group, as my job is to meet and maintain this conformance at a large organization. I'm learning quite a bit from all of you.

I've been following this particular topic with a keen interest in seeing what a "margin of error" would be defined as, in part because our company is about to launch into a major site consolidation and I'm curious about how to scale our current testing process.  Until now, we've actually been testing every page we can with both automated scans and manual audits. 

>From a purely layman's point of view, the only confidence I have when testing medium to large volume websites (greater than 500 pages) is by doing the following:

1. automated scans of every single page
2. manual accessibility testing modeled after the user acceptance test cases to test the critical user paths as defined by the business
3. manual accessibility testing of each page type and/or widget or component (templates, in other words)

So, I felt the need to chime in on "margin of error," because it worries me when we start quantifying a percentage of error. I see this from the corporate side.  Putting a percentage on this may actually undermine the overall success of accessibility specialists working inside of a large organization.  We may find ourselves with more technical compliance and less overall usability for disabled users. As for me, I need to be able to point to an evaluation technique that encompasses more than a codified measurement in my assessment of a website's conformance.  Ideally, the  really needs to account for user experience.  It's one of the fail safes in the current 508 Compliance requirements that I've taken shelter in, actually, as outdated as they are - functional performance criteria.

I really appreciate the work everyone in this group is doing, as I will likely be a direct recipient of the outcome as I put these concepts into action over the course of their creation.  Consider me the intern who will try to see if these dogs will hunt. :)

Much appreciated,

On Thu, Jan 12, 2012 at 8:10 PM, Vivienne CONWAY <v.conway@ecu.edu.au> wrote:

  Hi Alistair and TF
  You have raised an interesting point here.  I'm thinking I like your idea better than the 'margin of error' concept.  It removes the obstacle of trying to decide what constitutes an 'incidental' or 'systemic' error.  I thnk it's obvious that most of the time a website with systemic errors would not pass, unless it was sytem-wide and didn't pose any serious problem ie.a colour contrast that's .1 off the 4.5:1 rule.  I think I like the statement idea coupled with a comprehensive scope statement of what was tested.


  Vivienne L. Conway, B.IT(Hons)
  PhD Candidate & Sessional Lecturer, Edith Cowan University, Perth, W.A.
  Director, Web Key IT Pty Ltd.
  Mob: 0415 383 673

  This email is confidential and intended only for the use of the individual or entity named above. If you are not the intended recipient, you are notified that any dissemination, distribution or copying of this email is strictly prohibited. If you have received this email in error, please notify me immediately by return email or telephone and destroy the original message.
  From: Alistair Garrison [alistair.j.garrison@gmail.com]
  Sent: Thursday, 12 January 2012 6:41 PM
  To: Shadi Abou-Zahra; Eval TF; Eric Velleman
  Subject: Re: EvalTF discussion 5.5


  The issue of "margin of error" relates to the size of the website and the number of pages actually being assessed.  I'm not so keen on the "5% incidental error" idea.

  If you assess 1 page from a 1 page website there should be no margin of error.
  If you assess 10 pages from a 10 page website there should be no margin of error.
  If you assess 10 pages from a 100 page website you will have certainty for 10 pages and uncertainty for 90.

  Instead of exploring the statistical complexities involved in trying to accurately define how uncertain we are (which could take a great deal of precious time) - could we not just introduce a simple disclaimer e.g.

  "The evaluator has tried their hardest to minimise the margin for error by actively looking for all content relevant to each technique being assessed which might have caused a fail."

  Food for thought...


  On 12 Jan 2012, at 10:04, Shadi Abou-Zahra wrote:

  > Hi Martijn, All,
  > Good points but it sounds like we are speaking more of impact of errors rather than of the incidental vs systemic aspects of them. Intuitively one could say that an error that causes a barrier to completing a task on the web page needs to be weighted more significantly than an error that does not have the same impact, but it will be difficult to define what a "task" is. Maybe listing specific situations as you did is the way to go but I think we should not mix the two aspects together.
  > Best,
  >  Shadi
  > On 12.1.2012 09:41, Martijn Houtepen wrote:
  >> Hi Eric, TF
  >> I would like to make a small expansion to your list, as follows:
  >> Errors can be incidental unless:
  >> a) it is a navigation element
  >> b) the alt-attribute is necessary for the understanding of the information / interaction / essential to a key scenario or complete path
  >> c) other impact related thoughts?
  >> d) there is an alternative
  >> So an unlabeled (but required) field in a form (part of some key scenario) will be a systemic error.
  >> Martijn
  >> -----Oorspronkelijk bericht-----
  >> Van: Velleman, Eric [mailto:evelleman@bartimeus.nl]
  >> Verzonden: woensdag 11 januari 2012 15:01
  >> Aan: Boland Jr, Frederick E.
  >> CC: Eval TF
  >> Onderwerp: RE: EvalTF discussion 5.5
  >> Hi Frederick,
  >> Yes agree, but I think we can have both discussions at the same time. So:
  >> 1. How do we define an error margin to cover non-structuraal errors?
  >> 2. How can an evaluator determine the impact of an error?
  >> I could imagine we make a distinction between structural and incidental errors. The 1 failed alt-attribute out of 100 correct ones would be incidental... unless (and there comes the impact):
  >>   a) it is a navigation element
  >>   b) the alt-attribute is necessary for the understanding of the information / interaction
  >>   c) other impact related thoughts?
  >>   d) there is an alternative
  >> We could set the acceptance rate for incidental errors. Example: the site would be totally conformant, but with statement that for alt-attributes, there are 5% incidental fails.
  >> This also directly relates to conformance in WCAG2.0 specifically section 5 Non-interference.
  >> Eric
  >> ________________________________________
  >> Van: Boland Jr, Frederick E. [frederick.boland@nist.gov]
  >> Verzonden: woensdag 11 januari 2012 14:32
  >> Aan: Velleman, Eric
  >> CC: Eval TF
  >> Onderwerp: RE: EvalTF discussion 5.5
  >> As a preamble to this discussion, I think we need to define more precisely ("measure"?) what an "impact" would be (for example, impact to whom/what and what specifically are the consequences of said impact)?
  >> Thanks Tim
  >> -----Original Message-----
  >> From: Velleman, Eric [mailto:evelleman@bartimeus.nl]
  >> Sent: Wednesday, January 11, 2012 4:15 AM
  >> To: public-wai-evaltf@w3.org
  >> Subject: EvalTF discussion 5.5
  >> Dear all,
  >> I would very much like to discuss section 5.5 about Error Margin.
  >> If one out of 1 million images on a website fails the alt-attribute this could mean that the complete websites scores a fail even if the "impact" would be very low. How do we define an error margin to cover these non-structural errors that have a low impact. This is already partly covered inside WCAG 2.0. But input and discussion would be great.
  >> Please share your thoughts.
  >> Kindest regards,
  >> Eric
  > --
  > Shadi Abou-Zahra - http://www.w3.org/People/shadi/
  > Activity Lead, W3C/WAI International Program Office
  > Evaluation and Repair Tools Working Group (ERT WG)
  > Research and Development Working Group (RDWG)

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Received on Saturday, 14 January 2012 01:33:49 UTC

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