- From: Charles McCathieNevile <charles@sidar.org>
- Date: Tue, 19 Apr 2005 19:54:28 +0200
- To: "Paul Walsh" <paul.walsh@segalamtest.com>, "'Nils Ulltveit-Moe'" <nils@u-moe.no>
- Cc: "'Giorgio Brajnik'" <giorgio@dimi.uniud.it>, public-wai-ert@w3.org
On Tue, 19 Apr 2005 11:32:01 +0200, Paul Walsh <paul.walsh@segalamtest.com> wrote: (I think this bit was Nils - CMN) > I appreciate that. With such a profile your testers would most probably > be quite confident in their decisions, and if you are 100% confident > that an accessibility issue is real, then the extra confidence value is > not needed. (i.e. the default value for confidence, if it is left out, > is 1). > [PW] Every 'validation' company needs to follow the same process > irrespective of experience. That way, the output of the 'team' will be > 100 confident in their interpretation of the checkpoint passing or > failing. If they are not, then you have an issue with that company's > capabilities and/or understanding of the checkpoints. This is why I want to have a variety of confidence datatypes. In principle you would have one per test process, but in practice there are going to be lots of overlaps - for example if 100 different tests, run according to Nils' process, give probability results accurate to 2 significant figures, then it is probably OK to use the same datatype for all of them On the other hand if I use a different process for a similar test, and its results are different, I should use a different datatype. That way it is possible to compare the results more accurately if I know more about the differences in how the confidence is generated. The sort of examples that spring to mind are to do with the accuracy of meters, or of labelling on resistors, not WCAG conformance. For WCAG I think these comparisons, and for that matter many confidence level sets, are going to be based on smaller sets - High medium low, integer from 1 to 7, etc. I suspect I still haven't made this very clear. Any hints? cheers Chaals -- Charles McCathieNevile Fundacion Sidar charles@sidar.org +61 409 134 136 http://www.sidar.org
Received on Tuesday, 19 April 2005 17:54:52 UTC