- From: Hansen, Eric <ehansen@ets.org>
- Date: Tue, 05 Sep 2000 15:17:28 -0400
- To: "UA List (E-mail)" <w3c-wai-ua@w3.org>
To: UA List From: Eric Hansen Re: Scoring Example User Agents Suggestion 1: Determine whether there needs to be any adjustment in checkpoints due to the new focus on "mainstream graphical user agents". The 1 September 2000 draft focuses in on "mainstream graphical user agents" and I presume that this excludes user agents that a specifically or exclusively for people with disabilities. This seems consistent with our earlier discussion of focusing on "general purpose user agents" and with the even earlier decision to focus on "general purpose graphical user agents". However, as I have said before, there does seem to be a bit of a mismatch between the checkpoints and this scope. For example, as currently written a user agent could achieve the triple-A level, yet not even be able to present graphics. Specifically, there are no requirements that the user agent be able to present any given media type. This still seems a bit unusual, especially given that the current definition of user agent ("A user agent is software that retrieves and renders Web content, including text, graphics, sounds, video, images, and other content types."), though I suppose that a more accurate definition of user agent would replace the word "including" with the words "such as".) My own concern about this mismatch waxes and wanes. Previous suggestions to add checkpoints requiring an ability to present certain media types have not been implemented. I mention it now because we may find that by making changes that I suggested earlier, we may help solve other problems as well. ======== Suggestion 2: Gather data to strengthen our understanding of some key questions related to assistive technologies, plug-ins, and add-ons, etc. The 1 September 2000 draft moves in the right direction by clarifying the relationship between the UAAG document and assistive technologies: "3.2 Which user agents are expected to conform" "Users with disabilities often require more than one user agent for full access to the Web. For example, a user might require a graphical desktop browser, a multimedia player, and specialized assistive technologies such as screen readers, which are useful for controlling speech output and refreshable braille display. This document focuses on the accessibility of mainstream user agents so that most users with disabilities will have access to the Web when using a conforming user agent in conjunction with assistive technologies. There are also requirements in this document to make user agents more accessible to those users with disabilities who do not require assistive technologies for full access." This paragraph is helpful and seems to reflect pretty well our current state of knowledge. Yet there are ambiguities. The second and first sentences imply that a combination of technologies -- "graphical desktop browser, a multimedia player, and specialized assistive technologies" are necessary to provide "full access". Yet the third sentence seems to indicate that the "conforming user agent" was treated as a singular user agent rather than as a composite (or combined) user agent. I think that we ourselves need to understand better how our document behaves when used under different, commonly occurring situations. The need for further clarification was highlighted in my own case when I realized how unsure I was about the answers to some of the following questions. a. No DOM Support in Component of a Composite User Agent True or False: "It is possible for a user agent that does not implement the DOM to be a component of a composite user agent that achieves any of the three levels of claim (single-A, double-A, and triple-A)." Answer: True (?). I thought that there was going to be some indication that checkpoints 5.1, 5.2, etc., _cannot_ be considered inapplicable but I don't see them so I give "True" as the correct answer. I have not examined the document fully, but I don't see such a provision. ==== b. No DOM Support in Singular User Agent True or False: "It is possible for a singular (non-composite) user agent to not implement the DOM and yet achieve any of the three levels of claim (single-A, double-A, and triple-A)." Answer: True (?). See answer for "a." ==== c. Text Reader Within Composite User Agent True or False: "It is possible for a text reader (e.g., screen reader) user agent to be a component of a user agent that achieves any of the three levels of claim (single-A, double-A, and triple-A)." Answer: True (?). ==== d. Text Reader in Singular User Agent True or False: "It is possible for a text reader (e.g., screen reader) user agent to be a singular (non-composite) user agent that achieves any of the three levels of claim (single-A, double-A, and triple-A)." Answer: True (?), though based on the focus on mainstream graphical user agents it would not make sense to analyze a singular user agent of this type. ==== e. Braille Within Composite User Agent True or False: "It is possible for a braille display user agent to be a component of a user agent that achieves any of the three levels of claim (single-A, double-A, and triple-A)." Answer: True (?). ==== f. Braille Singular User Agent True or False: "It is possible for a braille display user agent to be a singular (non-composite) user agent that achieves any of the three levels of claim (single-A, double-A, and triple-A)." Answer: True (?), though based on the focus on mainstream graphical user agents it would not make sense to analyze a singular user agent of this type. ==== g. Advantages and Disadvantages Open Ended: "Describe the advantages and disadvantages for the developer of a 'mainstream graphical user agent' analyzing their user agent as part of a composite user agent that includes one or more of the following: multimedia player, Braille display, and screen reader package." Answer: Not sure. I think that one thing that must be kept in mind by someone answering this question is that the subject of each checkpoint is the subject of the claim. This means, for example, that if a composite user agent includes a Braille display, then the "user interface" in checkpoints such as 1.1, 1.3, 1.5, 2.1, 5.2, 5.4, 5.5, 5.8, 8.7, 10.9, should refer to the interface of the Braille display as well as to whatever may be presented in other display devices. Conclusion: I would suggest asking one or more people to score the following user agents. If only a few of the following could be done, I might suggest focusing on numbers 1, 5, 8, and 11. I think that all these cases would be helpful. 1. Singular user agent = mainstream graphical user agent 2. Singular user agent = multimedia player 3. Singular user agent = screen reader package 4. Singular user agent = Braille display 5. Composite user agent = mainstream graphical user agent + multimedia player 6. Composite user agent = mainstream graphical user agent + screen reader package 7. Composite user agent = mainstream graphical user agent + Braille display 8. Composite user agent = mainstream graphical user agent + multimedia player + screen reader package 9. Composite user agent = mainstream graphical user agent + multimedia player + Braille display 10. Composite user agent = mainstream graphical user agent + screen reader package + Braille display 11. Composite user agent = mainstream graphical user agent + multimedia player + screen reader package + Braille display 12. Singular user agent = text-only browser 14. Singular user agent = audio-only (telephone) browser 15. Singular user agent = audio-and-text (telephone) browser * I think that by examining the claims that would result from these various cases, we would be better able to guide people in including or excluding user agents from the analyses. The more of these cases we can examine, the better we will be able to eliminate bugs and other problems that might now exist in the document. Without this kind of analysis, I am not sure that we can properly judge the impact of our recent decisions to (a) allow composite user agents and (b) focus more narrowly on 'mainstream graphical user agents'. Examples of results that would be of particular interest might include: unexpected increases or decreases in conformance when some kind of component is added; unusually high or low numbers of inapplicable checkpoints; higher accessibility ratings for non-graphical or specialized user agents than for mainstream graphical user agents, etc. Even if such results caused no changes to checkpoints, they might result in changes how we tell people to make the best use of the UAAG document. It seems to me that we need not only (a) example implementations of individual checkpoints but also (b) example scorings of user agents (singular and composite) that people may want to try to use the guidelines to analyze. Does this make any sense? =========================== Eric G. Hansen, Ph.D. Development Scientist Educational Testing Service ETS 12-R Princeton, NJ 08541 609-734-5615 (Voice) E-mail: ehansen@ets.org (W) 609-734-5615 (Voice) FAX 609-734-1090
Received on Tuesday, 5 September 2000 15:17:51 UTC