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RE: Definition of human testability

From: Charles McCathieNevile <charles@w3.org>
Date: Sun, 2 May 2004 02:55:50 -0400 (EDT)
To: Gregg Vanderheiden <gv@trace.wisc.edu>
Cc: w3c-wai-gl@w3.org
Message-ID: <Pine.LNX.4.55.0405020248180.313@homer.w3.org>

Sorry, my point was more subtle. I understand the general principle of
agreeing on the results of tests. (This is why I participate in
EuroAccessibility under my Sidar hat - Sidar thinks it is very important
that we clarify and agree on how to test WCAG 1, at least across Europe).

But we often seem to be saying "for things that aren't machine testable, we
want to get consistent results from people". And I just wanted to clarify
that we expect all tests to be testable by people, with consistent results,
including those that are often automated.

For example, validation of HTML and XHTML code is something that machines do
more efficiently than people, and on average more accurately. But there are
bugs from time to time in validators, which a group of people who know the
relevant specification can all identify. In such a case, I believe we want to
say that the people are right and the machine test is wrong. Otherwise it
will be necessary to identify the particular machine tests we trust, which I
think will add about 2 years to the timeline...

cheers

Chaals

On Sat, 1 May 2004, Gregg Vanderheiden wrote:

>I'm not following you Charles.
>
>What this says - is that all success criteria must be reliably testable.
>That is, we can't have success criteria like "Write clearly" since 10 users
>would differ on what constituted 'clearly'.     The test cannot be more
>specific than the guideline, so all the testers could go on was their own
>training for what constituted 'clearly'.
>
>NOTE: that it is not yet clear whether all of the SC we have are specific
>enough to be reliably testable without referring to technology specific
>checklists.  But that is another discussion.  Hopefully we can make them
>specific enough in the doc.  What the consensus is though - is just that we
>should not have anything listed in the SC category that an author cannot
>reliably determine (or have determined) that they have met.
>
>Make sense now?  If not - then we need to figure out how to word it better.
>
>
>Gregg
>
> -- ------------------------------
>Gregg C Vanderheiden Ph.D.
>Professor - Ind. Engr. & BioMed Engr.
>Director - Trace R & D Center
>University of Wisconsin-Madison
>
>
>-----Original Message-----
>From: Charles McCathieNevile [mailto:charles@w3.org]
>Sent: Saturday, May 01, 2004 12:41 PM
>To: Gregg Vanderheiden
>Cc: w3c-wai-gl@w3.org
>Subject: RE: Definition of human testability
>
>This seems backwards. Presumably we believe that all tests will produce
>consistent results when done by reasonably knowledgeable people, with some
>of
>them also being sufficiently simple to automate completely.
>
>Otherwise we have no basis for deciding whether a particular test that a
>tool
>does is in fact a valid one or not, and in the case of two conflicting
>results from tools we would not have any way of declaring which was
>accurate...
>
>cheers
>
>Chaals
>
>On Thu, 29 Apr 2004, Gregg Vanderheiden wrote:
>
>>Yes
>>
>>That is what is intended I believe.
>>
>>Your alternative wording #1 is closest.   The word "certain" isn't quite
>>right since it would apply to all of the non-machine testable items   so it
>>would become
>>
>>
>>
>>1. In the judgment of the working group members, the success criteria that
>>are not machine testable can be tested by humans in a manner that is
>capable
>>of yielding consistent results among multiple knowledgeable testers.
>>
>>
>>
>>
>>Gregg
>>
>> -- ------------------------------
>>Gregg C Vanderheiden Ph.D.
>>Professor - Ind. Engr. & BioMed Engr.
>>Director - Trace R & D Center
>>University of Wisconsin-Madison
>>
>>  _____
>>
>>From: w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org] On
>Behalf
>>Of Sailesh Panchang
>>Sent: Thursday, April 29, 2004 11:22 AM
>>To: w3c-wai-gl@w3.org
>>Subject: Definition of human testability
>>
>>
>>
>>    Present draft: "Success criteria for all levels would be testable.
>>Some success criteria
>>may be machine-testable. Others may require human judgment.
>>Success criteria that require human testing would, in the judgment of the
>>working group members,  yield consistent results among multiple
>>knowledgeable testers."
>>Comment:
>>Wording of the last sentence is confusing. I believe what is meant is:
>>"Judgment of the working group members" applies to identification of
>>criteria that can be tested with  consistency  and reliability  by humans.
>>Right?
>>Do we intend to list these tests?
>>Consider following alternatives:
>>1. In the judgment of the working group members, certain success criteria
>>can be tested by humans in a manner that is capable of yielding consistent
>>results among multiple knowledgeable testers.
>>
>>
>>
>>2. Claims of conformance  to success criteria can be based on human testing
>>is such testing has yielded or is capable of yielding consistent results
>>among multiple knowledgeable testers.
>>
>>Sailesh Panchang
>>
>>Senior Accessibility Engineer
>>Deque Systems,11180  Sunrise Valley Drive,
>>4th Floor, Reston VA 20191
>>Tel: 703-225-0380 Extension 105
>>E-mail: sailesh.panchang@deque.com
>>Fax: 703-225-0387
>>* Look up <http://www.deque.com> *
>>
>>
>>
>>
>>
>>
>>
>
>Charles McCathieNevile  http://www.w3.org/People/Charles  tel: +61 409 134
>136
>SWAD-E http://www.w3.org/2001/sw/Europe         fax(france): +33 4 92 38 78
>22
> Post:   21 Mitchell street, FOOTSCRAY Vic 3011, Australia    or
> W3C, 2004 Route des Lucioles, 06902 Sophia Antipolis Cedex, France
>
>

Charles McCathieNevile  http://www.w3.org/People/Charles  tel: +61 409 134 136
SWAD-E http://www.w3.org/2001/sw/Europe         fax(france): +33 4 92 38 78 22
 Post:   21 Mitchell street, FOOTSCRAY Vic 3011, Australia    or
 W3C, 2004 Route des Lucioles, 06902 Sophia Antipolis Cedex, France
Received on Sunday, 2 May 2004 02:55:50 GMT

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