- From: Denis Anson <danson@miseri.edu>
- Date: Thu, 15 Mar 2001 13:34:47 -0500
- To: "'Ian Jacobs'" <ij@w3.org>, <w3c-wai-ua@w3.org>
Some comments on the current draft, in preparation for the meeting: Abstract: By following these guidelines, developers will create more usable software for all Web users. [DA: Actually, only for users of the browser in question. Web authoring guidelines improve access for anyone who accesses a page, but UA guidelines only help those using a specific user agent. What we really mean is that following the guidelines will improve access for all uses of the user agent, including those with disabilities.] In Section 1.1: . UAAG 1.0 includes several repair requirements (e.g., checkpoints checkpoint 2.7 and checkpoint 2.10) for cases where content does not conform to WCAG 1.0. Furthermore, some requirements in this document support authoring practices that may be widely deployed but that are discouraged because they cause accessibility or usability problems (e.g., some uses of HTML frames).[DA: This seems to be saying that this document is supporting practices that cause access problems! Surely that isn't what we mean.] Guideline 1: People who cannot or do not use a mouse have to be able to operate the user interface with the keyboard, through voice input, a head wand, touch screen, or other device. [DA: In this context, a head-wand is a means of accessing the keyboard, and a touch screen is generally a mouse emulator, so these examples are actually just restating mouse and keyboard. Why not consider input methods there that do not rely on standard mouse and keyboard presence: such as Morse Code or single-switch scanning. ] Checkpoints 1.1 through 1.3 [DA: As written, this seems to say that you can choose to implement mouse only, keyboard only, or voice input only interfaces, and claim such conformance. I understood us to intend that you must provide keyboard interface, and may provide mouse and voice interfaces. Even devices that do not have keyboards should have an API that supports keyboard control to facilitate use of AT. ] Guideline 2 text include: . Local control of rendering is important; global configuration of . Local control of rendering is important; global configuration of rendering preferences is convenient for access. Checkpoint 2.2 2.2 For all text formats that the user agent implements, provide a view of the text source. [Priority 1] Note: The user agent should provide a source view for any text format, not just implemented text formats. Text formats include all of the following: [DA:The note here sets a different standard than the checkpoint. The checkpoint says that source view is required for formats that are implemented. The note says that source view is required whether or not the format is implemented!] 2.3 Allow configuration so that, for each piece of unrendered conditional content "C" the user agent alerts the user to the existence of the content and provides access to it. Provide access to this content according to format specifications or where unspecified, as follows. If C has a close relationship (e.g., C is a summary, title, alternative, description, expansion, etc.) with another piece of rendered content D, do at least one of the following: (1) render C in place of D, (2) render C in addition to D, (3) provide access C by querying D, or (4) allow the user to follow a link to C from the context of D. Otherwise, do at least one of the following: (1) render a placeholder for C that may be replaced by C, (2) provide access to C by query (e.g., allow the user to query an element for its attributes), or (3) allow the user to follow link in context to C. [Priority 1] [DA: Does this include the option of notifying an external AT, via an API, of the existence of C, so that the AT can access and render C outside of the user agent itself?] 2.4 For content where user input is only possible within a finite time interval controlled by the user agent, allow configuration to make the time interval "infinite". Do this by pausing automatically at the end of each time interval where user input is possible, and resuming automatically after the user has explicitly completed input. In this configuration, alert the user when the session has been paused and which enabled elements are time-sensitive. [Priority 1] DA: Does this include the condition where there are embedded links inside a QuickTime movie, for example, that allow a user to further explore building shown in the movie? There, input is only possible when the particular building is on the screen, but when following 2.4, the user would have to explicitly say whether or not to follow each link that appeared. Would such a decision be persistent across frames? It looks like the movie would have to pause just before each link passed "out of view." 2.7 Allow configuration to generate repair text when the user agent recognizes that the author has failed to provide conditional content that was required by the format specification. If the missing conditional content is included by URI reference, base the repair text on the URI reference and content type. Otherwise, base the repair text on element type information. [Priority 2] DA: I agree with Ian here that the information in the URI is a minimal, but certainly not optimal repair text. This might be the minimum implementation, but other solutions should be supported. 2.9 Allow configuration to create the conditions under which conditional content is rendered. [Priority 3] Note: DA: I'm not sure what this means. Doesn't conditional text, by definition, have attached conditions? Perhaps we mean that the user agent should allow configuration to modify the conditions under which conditional text is rendered? 3.1 Allow configuration not to render background images. In this configuration, provide an option to alert the user when a background image is available (but has not been rendered). [Priority 1] Content type labels: Image. Note: This checkpoint only requires control of background images for "two-layered renderings", i.e., one rendered background image with all other content rendered "above it". When background images are not rendered, user agents should render a solid background color (see checkpoint 4.3). In this configuration, the user agent is not required to retrieve background images from the Web. Techniques for checkpoint 3.1 DA: Would a background image in a table that overlies a background image on a page still meet this standard? We now have at least 3 layers of rendering. 3.3 Allow configuration to render animated or blinking text as motionless, unblinking text. [Priority 1] Content type labels: VisualText. Note: This checkpoint does not apply for blinking and animation effects that are caused by mechanisms that the user agent cannot recognize. This checkpoint requires configuration because blinking effects may be disorienting to some users but useful to others, for example users who are deaf or hard of hearing. [DA: If a <marquee> contained more text than would fit in the allotted space, would the user agent have to rerender the page to make the text visible?] 3.5 Allow configuration so that client-side content refreshes (i.e., those initiated by the user agent, not the server) do not change content except on explicit user request. Allow the user to request the new content on demand (e.g., by following a link or confirming a prompt). Alert the user, according to the schedule specified by the author, whenever fresh content is available (to be obtained on explicit user request). [Priority 1] DA: Consider this scenario: The user is informed via a dialog that refresh content is available, and is asked whether or not to render it. Because s/he is not ready yet, s/he responds "NO," which dismisses the dialog. How do you get the dialog back when it's time for a refresh? There would have to be a keyboard equivalent, yes? 3.7 Allow configuration not to render images. In this configuration, provide an option to render a placeholder in context for each unrendered image. When placeholders are rendered, allow the user to activate each placeholder individually and replace it with the original author-supplied content. [Priority 2] DA: For this, part of the configuration should be to render the content serially on demand. If the reason for suppression of the images is that a complex screen overwhelms the user, then sequentially activating images would eventually reach the level at which the user is overwhelmed. If the images were activated serially, then activating one image would suppress images that had previously been rendered, maintaining the level of complexity of the page. I'll continue and send more. Denis Anson, MS, OTR/L Assistant Professor College Misericordia 301 Lake St. Dallas, PA 18612
Received on Thursday, 15 March 2001 13:37:22 UTC