- From: Ian Jacobs <ij@w3.org>
- Date: Wed, 23 Jun 1999 10:34:43 -0400
- To: Harvey Bingham <hbingham@ACM.org>
- Cc: w3c-wai-ua@w3.org
Harvey Bingham wrote:
(Note: I've integrated Harvey's comments that are unanswered
here into the document for the next revision.)
> Table of Contents
>
> Final para: "The appendix list of checkpoints ...
>
> [Neither appendix is in TOC. Not clear that it is an appendix. Perhaps
> refer to them just as Checkpoints, analogous to Techniques.]
They are actually in the TOC, but not in the <UL> of the TOC
(because they are external documents and I wanted to distinguish
them). Thus, after "6. References" of the <UL>, the following statement
indicates they are appendixes:
" The appendix list of checkpoints is available as either a
tabular summary of checkpoints or as a simple list of
checkpoints. "
There are more references to the fact that these are appendixes
to this document in the Status sectino.
> >1.1 Principles of Accessible Design
>
> >Ensure that the user interface is accessible.
>
> Para 2.
> >The general topic of user interface accessibility for computer software
> exceeds the scope of this document.
>
> I question that disclaimer. Nowhere else to my knowledge is this topic
> covered, and I think that is our charter. Given it, though, I believe
> mention that the UA-TECHNIQUES document indicates current user interface
> accessibility suggestions is appropriate.
Charles is working on a W3C Note that will include references to
vendor-specific guidelines for software accessibility. I would
like to refer to that Note once it's available.
> >Help Orient the User
>
> UL 2, LI 1.
> >...how many links the document contains or the number of the
> current link.
>
> I don't appreciate why the "number of the current" link is useful. What if
> some links reoccur? Are they counted? First occurrence number used?
This is meant to refer to element instances (not link text or link
destinations). Thus, every "A" element is numbered (uniquely). It's
useful to know that I'm on the 75th link of the document if I
have a navigation mechanism that lets me return to it (by number).
I admit, this is very technique-y as it suggests numbering links
as a way of letting readers know where they are. There are undoubtedly
other techniques. For this reason, I question whether these
checkpoints should be checkpoints at all (to be discussed at the
23 June teleconf).
>UL 2, LI 2.
> [Should a "download progress" indication be available?]
Refer to checkpoint 8.14
> [Should we include a suggestion to download text and ALT="..." before images?]
This could appear in the techniques document, but in my opinion
goes to far in suggesting an implementation. The purpose of the
checkpoint is not to ensure fast downloads (though this is interesting)
but to provide a measure of progress (whatever the speed).
> >3.1 Conformance
>
> >Conformance claims
>
> [Suggest if dependent UA, further qualify limits expected by that UA.
I'm not sure what this means. Can you give an example?
> Final Note:
> [Do we expect that the dated version of the guidelines will drop the
> date in the event this document becomes a W3C Recommendation?]
No. Conformance will refer to a specific, frozen version of the
specification, not the latest version.
> >4. User Agent Accessibility Guidelines
>
> >Please note that "device-independent support" does not mean that user agents
> must support every input or output device. User agents should offer redundant
> input and output mechanisms for those devices that are supported. For example,
> if a user agent supports keyboard and mouse input, users should be able to
> interact with all features using either the keyboard or the mouse.
>
> [? I am uncertain that mouse needs to provide all keyboard capabilities?]
That's an interesting point. For example, must I be able to type
via the mouse (e.g., by using an entry palette)?
> [General questions:
> How handle the bootstrap process to get started: what can be assumed:
> operating system, file system, available device "plug & play"?]
For generality, we should not assume an operating system or
file system (e.g., when using a kiosk). Where should we mention this?
> >3.2 Describe product features known to promote accessibility in a section of
> the product documentation. [Priority 2]
>
> [How find these initially?]
There is information about this in the Techniques Document
(3.9.1 of 11 June version).
> >4.8 Allow the user to turn on and off support for scripts and applets.
> [Priority 1]
> Note. This is particularly important for scripts that cause the screen to
> flicker, since people with photosensitive epilepsy can have seizures triggered
> by flickering or flashing in the 4 to 59 flashes per second (Hertz) range.
>
> [I believe european frequency is 50 Hz. I expect that 59 Hz value was picked
> to be just below the 60 Hz. US/Canadian AC power frequency. I note that
> the effective 30 Hz of US TV interlace seems to violate the above as well.
>
> This should have been caught in the Web Content Guidelines.]
Jon has flagged this as an issue for discussion.
> >4.10 Allow the user to turn on and off support for author style sheets.
>
> [Does this mean substitute for author style sheets, in part or completely,
> using the CSS cascading and IMPORTANT indications?
>
> Or was the intent: audible, rather than author? If author, should audible
> style sheets be a separate list item?]
I would suggest that "support for author style sheets" means that
they are parsed and cascaded with other style sheets according to
the style sheet spec. Turning off support would mean they are ignored.
> >4.13 ?automatic page forwarding?
> [I'm unfamiliar with this, is it a "feature" of existing browsers?]
Some browsers support META element declarations such as this:
<META http-equiv="refresh" content="5; http://www.acme.com/newpage">
After a 5-second delay, the new page is loaded.
> >5.8 Allow the user to control video frame rates.
>
> [That presumes adequate net support for bandwidth and non-interruption.]
It sounds like there are two scenarios: streamed video and
local playback. Does is matter which type the user is viewing?
> >5.11 Allow the user to control audio playback rate.
>
> [That presumes adequate net support for bandwidth and non-interruption.]
> >6.8 Allow the user to specify that captions for audio be rendered
> at the same time as the audio.
>
> [replaced "at the same time" by "synchronized with"]
> [Similarly for 6.11 and 6.12]
I think "at the same time" doesn't mean "synchronized with"
in this case, but rather that both are rendered. In other words,
when captions are available (and as captions they are
already synchronized), all the user to view them while the video
is running (as opposed to captions-only).
> >Guideline 7...
>
> >Note:
>
> [why is the style for the selection and the focus link different from
> that for active elements?]
The focus is a mechanism used to identify active elements. It may
not be the only mechanism.
> >7.5 Allow the user to navigate directly to active elements in the document.
> [Priority 2] For instance, the user might navigate directly by selecting the
> number of a link or by entering the first letter of link text.
>
> [Why would these numbers on links (or of links) be known?
> In the case of repeated first letters of link text that are repeated,
> move to next so-starting, case independent.]
See comment above about numbering "A" elements.
>
> >8.8 For dependent user agents. Allow the user to view a document outline
> constructed from its structural elements (e.g., from header and list elements).
> [Priority 2]
>
> [Not all list elements have any identification that would help to
> differentiate structure.]
Which list elements are those? I think the word "element" is supposed
to suggest markup.
> >8.16 Make available whether a chosen link has already been visited.
>
> [even if multiple instances of that link occur in the document.]
A "chosen link" means a particular A element, not the content
of the element or the destination of the link.
Thank you for the comments Harvey!
- Ian
--
Ian Jacobs (jacobs@w3.org) http://www.w3.org/People/Jacobs
Tel/Fax: +1 212 684-1814
Received on Wednesday, 23 June 1999 10:33:46 UTC