- From: Al Gilman <Alfred.S.Gilman@IEEE.org>
- Date: Fri, 12 Aug 2005 14:35:58 -0400
- To: w3c-wai-gl@w3.org
- Cc: wai-liaison@w3.org
<note class="concurrence process"> The basic ideas presented in the draft below have gained a rough consensus in the PF Working Group. PFWG is seeking feedback from the guidelines groups (User Agent, Web Content, Authoring Tools) before representing this as a WAI position. The draft has been edited with the benefit of some friendly amendments from the User Agent Working Group who were also in general agreement. Also some "authors and authoring" issues have been appended where your topic is involved and your feedback is desired. Please put this up for consideration [in the Techniques Task Force?] and let me know when it will be on the agenda for a telecon if it will be discussed in real time in that way. Thank you for your attention to this. Al </note> <position class="DRAFT senseOfTheWAI"> Topic: Features in XHTML 2.0 and future Web formats in the area of functionality similar to the 'accesskey' functionality in HTML 4. Requirements: 1. The user must be able to request and be told what hotkeys have been enabled by the web page or application through a Browser function. The user must be able to re-bind outcomes that are accelerated in this way to be triggered by alternate user input gestures. The user does not have to be able to substitute arbitrary UI events. But the substitution ability must be rich enough to work around collisions between web-defined hotkeys and the system and browser environment, and to work around non-usability of a particular UI event by a particular person or their client device. The user must be able to replace aggressive outcomes (at least 'activate' actions) to more step-by-step procedures (by substituting a 'focus' event targeted to the same object). 2. This ability to review and control, including alter, the binding of UI events to accelerators must be available through APIs so that assistive technology can exercise this control. 3. Given that these two are satisfied, it is not appropriate to limit accelerators to those defined on the client side by the OS, browser, AT and user. The capability should be maintained for there to be author-defined nominations of mnemonic hotkeys [or other author-identified default trigger-event bindings] for accelerators specific to the current context in a web application. Rationale: 1. UAAG Guideline 1 http://www.w3.org/TR/UAAG10/guidelines.html#gl-device-independence Note: The language about user review and adjustment of input event bindings that is found in an informative passage in the XForms recommendation at <quote cite=" http://www.w3.org/TR/xforms/slice8.html#id2625797 "> The user agent must provide a means of identifying the accesskeys that can be used in a presentation. This may be accomplished in different ways by different implementations, for example through direct interaction with the application or via the user's guide. The accesskey requested by the author might not be made available by the player (for example it may not exist on the device used, or it may be used by the player itself). Therefore the user agent should make the specified key available, but may map the accesskey to a different interaction behavior. </quote> .. would be part of the SMIL 2.0 Recommendation save for an editing error. 2. UAAG Guideline 6 http://www.w3.org/TR/UAAG10/guidelines.html#gl-accessible-interface 3. User-defined accelerators work with the user's recall vocabulary. Author-defined accelerators work with the user's recognition vocabulary. It is well known that the recognition vocabulary is much larger than the recall vocabulary. Allowing author-initiative accelerators greatly increases the number of accelerators available and used. People with motor impairments need accelerators because of a high cost of input action. People with sensory impairments need accelerators because of a high cost in time spent in non-visual display modalities. While people with visual impairments are less able to capitalize on accelerators that operate by recognition than are people with motor impairments, the best compromise capability for both groups is to allow both and allow the user with impaired accelerator-recognition cycle to configure their UI to build on their strengths. </position> <issues> There will be a temptation for authors to use more low-level means, specifically binding a hotkey to an event defined by element ID and event type, as opposed to identifying this action by binding the accelerator to some widely-recognized role that this element fits. Sample roles would be "search: search the site or sub-site where this page is found," "home: go to the home page for the site where this page is found," etc. The low-level definition of the accelerator is bad for users who are better prepared to take advantage of accelerators associated with concepts that they recall rather than concepts the only recognize in the display of the content. In particular this makes it bad for screen reader users and superusers. On the other hand, using the more conceptual markup is not a detriment for the visual user, just more of a cognitive burden on the author (that we will want to ease by author tools). In terms of achieving recommendable web-markup practices while the author has the ability to create a hotkey with either more-conceptual or less-conceptual markup, there will be a burden that falls on the author advice (WCAG guidelines and techniques) and tools (ATAG techniques) to get authors to use the more-universal, more-conceptual markup features *where they apply.* [why no free lunch] If we try to force everyone to use access by role rather than access by targetEvent, people will pollute the role vocabulary with roles that are tantamount to specific target events after the manner that 'class' has been used as a synonym, not rationale, for presentation effects. And if we try to force the use of only standard roles, we cut off the ability to create application-specific accelerators. To get out of this bind, we pretty much need the WCAG techniques to both say and demonstrate the advice "mark your [page parts and] hotkey target elements with well-known 'role' values wherever they fit. And target your hotkeys in the most generic terms that get the right thing to happen (e.g. if there is only one 'search' tool on the page, or if a user might want to step through them if multiple, target a key to the 'search' role rather than to a particular element which is a container of the search tool). The ATAG techniques will need to promote author prompts that let the author just recognize the applicability of standard roles to their hotkey targets, rather than waiting for the author to volunteer that this target is actually performing some generic role. In other words the author should confirm, deny, or pick among a short list of heuristic-selected candidate roles and not have to enter a role name in a text box. The author tools should also prioritize hotkey targets for 'role' definition. There are lots of elements in a page that don't play a role we need to articulate. But not too many hotkey destinations that don't. Does the WCAG Techniques Task Force feel that, with that sort of support from authoring tools, authors in significant numbers would accept and follow access-positive practices in defining hotkeys for Web Applications? Is it worth taking the risk of relying on good usage here? Is the game worth the candle? Closer to home, should we just leave it to the separate working groups' Techniques documents to get out the word on this, or should we be thinking of this as a WG or CG Note to pull together the team of techniques that if all are used in their respective segments of the Web system, together create a service delivery pipeline that works. [This issue will naturally go back to WAI CG but your input would be helpful] </issues>
Received on Friday, 12 August 2005 18:36:15 UTC