- From: Shawn Henry <shawn@w3.org>
- Date: Mon, 04 Jan 2010 10:20:34 -0600
- To: Henrike Gappa <henrike.gappa@fit.fraunhofer.de>
- CC: wai-eo-editors@w3.org
Dear Henrike Gappa, Thank you very much for your comments. We will address these with the next revision of the documents. Regards, ~Shawn ----- Shawn Lawton Henry W3C Web Accessibility Initiative (WAI) e-mail: shawn@w3.org phone: +1.617.395.7664 about: http://www.w3.org/People/Shawn/ Henrike Gappa wrote: > Dear editors, > > Please find in the following some comments in regard to the posted notes: > > - Involving Users in Web Projects for Better, Easier Accessibility > (http://www.w3.org/WAI/users/involving) > - Involving Users in Evaluating Web Accessibility > (http://www.w3.org/WAI/eval/users) > > > To "Involving Users in Web Projects for Better, Easier Accessibility" > > We support wholeheartedly encouraging web site developers and owners to > conduct user testing for better accessibility. However, we feel that the > limitations of the proposed test methodology needs to be addressed much > more clearly. For instance, to stress that the test results obtained > with only a small group of disabled users can only be understood as > informative, also in regard to the generalization of test results to > users with the same characteristics, e.g., blind or screen-reader users. > There is a lot of diversity among people with the same disability even > when utilizing the same assistive technology. Furthermore, to our > knowledge, it is a precondition to have a deep insight into > accessibility guidelines and, at least to some extent, experience with > assistive technologies to really employ user testing for better > accessibility and to create accessible web applications. In other cases, > its benefit is more of motivational and educational nature which is of > great value and thus highly recommendable. The described issues are > somehow mentioned in the document, but should be pointed out much more > explicitly. For instance when contrasted with the section "More > Efficient Development", the limitations of the proposed methodology will > not be identified most likely by the uninformed user. > > Besides this, we are afraid it might not become clear to the reader > which user groups are addressed by the note. Most of the time the note > names only people with disabilities, sometimes it is people with > disabilities and older people and sometimes it is only "users", for > instance, in the section "More Efficient Development". > > Suggesting as test methodology to "ask a lot of questions" to gather > user data is vague. We propose to be more concrete. Since tests sessions > have a time limit, it is advisable for many test purposes to develop at > least a questionnaire guide to ensure that all relevant issues are > touched and that test results are comparable in case there are several > test participants. > > > > To "Involving Users in Evaluating Web Accessibility" > > Our first comment in regard to this note is -- as it was for "Involving > Users in Web Projects for Better, Easier Accessibility" -- that the > limitations of the described evaluation methodology need to be pointed > out more clearly. We are in favour of user testing, and agree that user > testing may reveal accessibility issues that would not have been > detected via standard conformance testing. However, it is also important > to note that many accessibility errors will definitely not be detected > by user testing alone. Therefore, different from what is stated in the > introduction of this article, to our knowledge, conformance checks to > all relevant accessibility guidelines are not only "important" but need > to be understood as the basic of all accessibility evaluations. We would > also suggest conducting a full review instead of a preliminary one and > fix all errors, before bringing in users to avoid operation errors of > the assistive technologies due to accessibility errors in the code. > > In the section on "Range of User Evaluation" informal vs. formal > usability evaluation are compared. We think it would be important to > also explain here differences of the outcome in terms of significance > and validity. Also gains and limitations of involving only a few people > with disabilities as stated in the section "Basics", should also be > pointed out clearly to the reader, so the reader is able to conclude > correctly what will be an appropriate test scenario for her purposes. In > the section "Drawing Conclusions and Reporting", the editors state the > need to be careful when "... drawing conclusions from limited evaluations > ....". However we feel that this is not explicit enough, because valid > conclusions cannot really be drawn from such user testing, and this > should be clear to the reader. The problem is not so much the lack of > statistical significance as mentioned, but the limited validity and > generalisability of test results. > > In the section on "Analyzing Accessibility Issues", it is proposed to > assign occurring accessibility issues to the origin, e.g., "the > developer did not markup/code the web page properly" or "the user's AT > isn't handling the markup properly". From our experience with > accessibility audits, this can only be achieved by accessibility > experts, which means for a reliable judgement, that the evaluator needs > to have deep knowledge about HTML, accessible web coding and standard > behaviour of AT. Otherwise, such mappings are in danger of being > error-prone. > > Finally, the section "More Information and Guidance" provides > information on user testing specifically for usability professionals. > Here, we do not really understand what is meant by "usability testing > for accessibility". Both, user testing for usability as well as > accessibility issues are based on methods and techniques derived from > Psychology and related sciences, e.g., work psychology or software > ergonomics. Thus to our understanding there are usability tests and > accessibility tests which follow different goals. They might overlap in > regard to certain sub-goals and methodologies employed, yet, the goal is > quite different and both disciplines should not be intermixed to our > understanding. > > Kind regards, > Henrike Gappa, Gabriele Nordbrock and Carlos Velasco > >
Received on Monday, 4 January 2010 16:20:35 UTC