- From: eric hansen <ehansen@ets.org>
- Date: Mon, 14 Dec 1998 18:12:42 -0500 (EST)
- To: w3c-wai-gl@w3.org
I would like to respond to comments made on 12/14/98 by Charles McCathieNevile (hereafter "CMc"). Note that "EH" indicates the responses of Eric Hansen. CMc: I am personally not keen on the idea of including elaborate impact statements, although there are a number in the guidelines. EH: I don't think that impact statements in the document would necessarily need to be more elaborate than what is included now. (Perhaps just a few refinements might be enough.) Currently the document highlights the _major_ affected disability groups and, in some cases, non-disability-related groups. I see the majority of impact data as non-normative and found in separate documents. CMc: I am dead against the idea of quantifying them, as I feel that is an exercise which is certainly beyond the scope, and probably beyond the resources of the WG. EH: I see some kind of quantification as valuable for ensuring the documents' audiences that the circumstances of key disability groups and been examined in the context of each guideline. I have generated draft impact ratings for 13 disability groups for 2 of the 17 guidelines. CMc: How much impact a particular problem has on the general community (as some kind of weighted average of impacts on subsections) is, in my opinion irrelevant to the goals of the group. It does not assist us to determine what guideines should be followed, and what techniques are available, to ensure that web content is accessible to all. EH: I think that impact ratings are one fairly stable piece of information that would go into figuring out which techniques should be followed. Specifically, impact ratings would be some of the information from which priority (importance) ratings would be derived. Furthermore, the impact ratings have the benefit of being much more focused than the priorities. (See earlier memos.) CMc: It is also important in such a situation to have accurate, up to date information. A W3C recommendation cannot be changed - it is by definition a stable document. [New para.] In this context, the removal of priorities on guidelines may be helpful. The guidelines themselves must be followed, but it may happen in some months that there is no necessity for most people to do anything particular to follow a given guideline, since the problem is handled for them by an authoring tool (as an abstract example). EH: Since earlier memos I have supported the idea that priorities don't belong in the normative portion of the document because they are too changeable. One of the major motivations for proposing the idea of "impacts" is to find a more stable indicator that might be included in the normative part (as well as providing a firmer conceptual anchoring of the guidelines to needs of specific disability groups). CMc: The priority definitions are information which may be useful to people trying to do a cost/benefit analysis - things which are priority 2 techniques are not going to provide access in themselves, they are just going to significantly improve the quality of that access (by bringing it nearer the quality experienced by 'mainstream users' - perhaps we should make that more explicit in the P2 definition?) while things which are priority 1 deal with the ability to access the information or function in any form, without minimal regard to the difficulty of using that information or function. EH: I think that it is very important to make explicit how the priorities are derived. If I understand the nature of priorities, I must disagree with your characterization of "priorities" as _input_ to the calculation of cost-benefit. My understanding has been that priorities are actually the _output_ from a calculation (albeit informal) that uses cost-benefit types of considerations (cost, feasibility, practicality, availability of tools, etc.) as input. How can one generate an indicator of the priority (or importance) related to a technique without consideration of the cost and availability of the tools for carrying out that technique? Indeed, it is such considerations that make priorities changeable. CMc: (It could be argued that giving a person access to a binary representation of the data in a GIF file is providing access, but I think most people would agree that it is a stupid argument.) EH: That particular example might easily be dismissed, but I will propose another one that is more realistic. Certain individuals who are deaf or are dyslexic can perceive the written text, but the text is just as inaccessible to them as if they cannot perceive it (if I am exaggerating, someone please correct me). A definition of priorities that assigns priority 1 to issues of perception and priority 2 to issues of language may give too little consideration to language-related issues even though they can be barriers that are just as severe. One may respond, "Yet issues of perception are more fundamental than issues of understanding or comprehension. Issues of perception deserve to have a higher priority than issues of understanding and comprehension." Yet, we should be aware that it is not very hard to recast issues of language as issues of perception. To illustrate this, I will propose a new technique or guideline: "If the written text is inaccessible, you must provide an alternative accessible version of the text." In other words, I as an individual with a severe print-related disability may say, "This technique is really no less important than the priority 1 technique of providing alternative text for graphics. This technique should be priority 1, not priority 2. The alternative, accessible text must be made perceptible to my senses." By the way, this proposed technique is not that "far out." This technique or guideline encompasses the material in A.7, at least some of the material in B.3, part of A.5, and so on. ============================= Eric G. Hansen, Ph.D. Development Scientist Educational Testing Service ETS 12-R Rosedale Road Princeton, NJ 08541 (W) 609-734-5615 (Fax) 609-734-1090 E-mail: ehansen@ets.org
Received on Monday, 14 December 1998 18:21:32 UTC