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Re: Kynn's Last Call Comments on CSS TV Profile 1.0

From: Tantek Çelik <tantek@cs.stanford.edu>
Date: Fri, 14 Jun 2002 03:45:47 -0700
To: Kynn Bartlett <kynn@idyllmtn.com>, www-style@w3.org
Message-id: <B92F176A.E4E2%tantek@cs.stanford.edu>

On 5/23/02 1:42 PM, "Kynn Bartlett" <kynn@idyllmtn.com> wrote:

> These comments address 15 May 2002 working draft, at
> http://www.w3.org/TR/2002/WD-css-tv-20020515


Thanks for your feedback!

I will try to address the issues you raise.

> Issue #1:
> I am very confused and troubled by the complete redefinition of the
> TV media in this document, compared to the CSS 2 definition.

CSS2 loosely defined the tv media type, without any actual industry
experience coming to bear with respect to using implementing CSS for TV
devices, and authoring CSS for TV devices.

Just as the CSS Mobile Profile[1] updates the definition of the 'handheld'
media type, the CSS TV Profile updates the definition of the 'tv' media

In both cases, domain experts that have experience with CSS in their domains
have provided a much more detailed and thought through profile of CSS for
their respective domains.

> In
> CSS 2, it states quite clearly (emphasis mine):
>     tv
>          Intended for televsion-type devices (low resolution, color,
>          limited-scrollability screens, SOUND AVAILABLE)

Yes, and at the time that was written, there was no experience with either
implementing or authoring CSS for TV devices.

Essentially, CSS2 did not have the benefit of "reality-checking" through the
CR phase which was adopted in W3C process years after CSS2 was published.

As a result (and this is not the only case), CSS2 contains many "good ideas"
which never came to fruition for one reason or another.

The CSS Working Group is deprecating, or in most cases, relabeling as
informative such "good idea - little or no implementation" CSS2 features in
CSS2.1.  One particular such area is the definition of the media types -
those definitions are for the most part all being made informative - since
such definitions would not successfully satisfy the implementation
requirements and thus exit CR.  The only thing normative about media types
that is being kept is the set of names of the media types, and the
definition of the 'all' media keyword.

> Under media groups, tv is defined as "visual, AURAL", unlike screen
> which is "visual."
> Television is universally understood to be a true multimedia medium,
> combining video and audio.
> However, the proposed TV profile does not acknowledge this.

The CSS TV Profile 1.0 refers to the appropriate CSS properties (and
selectors) from CSS2 that have either been demonstrated to be of use for TV
content specifically, or have been widely implemented and understood.

For now, the profile doesn't include any aural properties as you noted, but
the profile doesn't preclude the addition of multimedia support in a future

> All aural
> properties are unsupported in this profile, and aural values likewise
> are unsupported.

Unfortunately your evaluation of aural properties not only applies to the TV
profile, but in general.  Other than emacspeak (which AFAIK only implemented
a draft of the aural properties - not the final REC), which doesn't run on a
TV device AFAIK, the CSS working group doesn't know of any other
implementations, certainly not any interoperable implementations.

In order to encourage forward progress in the area of CSS Audio/Speech,
members of the CSS Working Group, along with other W3C audio/speech experts
(e.g. Dave Raggett, T.V. Raman etc.) discussed a course of action at the
most recent W3C plenary this past February/March.

There were several decisions made.  First, it was widely acknowledged that
the aural properties in CSS2 were a good first cut, useful for exploring the
field, but did not do a really thorough job of solving actual problems,
while containing esoteric ("neato") features (e.g. all the 3d audio stuff)
that were found to distract from the usefulness of the rest.  Thus, second,
it was decided to place the aural properties into an informative chapter of
CSS2.1, including documentation on what subset of those properties and
values had implementation experience (specifically T.V. Raman's
implementation experience), and what that experience has taught us.
Finally, third, it was decided that there should be a CSS3 Voice Module that
coordinated better with the VoiceML efforts, and that Dave Raggett would be
the editor for that module.

We are optimistic about a much improved set of aural properties and values
arriving in the CSS3 Voice Module, and until that arrives, we would rather
not reference CSS2 aural properties which we have already decided to move to
being informative and may not necessarily be supported moving forward.

> In addition wrongly identifying the tv medium,

The definition and identification of the tv medium in CSS TV Profile 1.0 is
more of a practical identification of the constraints of TV devices in use
today and in the near future.

> ignoring the audio
> aspects in this profile while accentuating only the visual will
> further relegate aural styles to the realm of "nice idea, never
> implemented beyond emacspeak."

It is actually the other way around.  Because we explicitly decided to
relegate the first generation of aural properties as a "nice idea" as you
say, it made sense to keep the 1.0 version of the CSS TV Profile simple,
with the hopes that once there is a "reality-checked" updated set of aural
properties in the CSS3 Voice Module, then a future version of the CSS TV
Profile can reference those.

> This can and will prove to be a
> detriment to users with visual disabilities.

Given that aural properties have not been widely implemented/deployed, and
certainly not on TV devices, it is difficult to see how simply acknowledging
that fact could be detrimental.

On the contrary, what would be more detrimental is trying to make something
work which has failed to take off for one reason or another.  It is our
sincere hope that Dave Raggett will assist with and produce a much better
CSS3 Voice Module than the ACSS chapter in CSS2.

> This draft should be sent back and rewritten to reflect the
> multimedia nature of the tv media type, as noted in CSS 2.

When support for multimedia properties is well defined in a CSS3 module and
at least at last call (preferably CR), then surely I can see someone writing
a 1.1 or newer version of the CSS TV Profile which then refers to those
multimedia properties.

I accept your input as a suggestion for a future version of the CSS TV
Profile - once multimedia properties have been properly improved, they
should be added to the next version of the CSS TV Profile.  I don't see such
additions conflicting with what is CSS TV Profile 1.0 (please let me know if
you do), so we can proceed with what we can make work today with 1.0, while
keeping in mind the ideal future for future versions.

> Issue #2:
> Section 6 of the proposal states that:
>     4.  The TV-UA SHALL support author originating style sheets.
>         The TV-UA MAY support user or user-agent originating
>         style sheets.
> User and user-agent style sheets are essential to ensuring equal
> access to CSS-based documents by people with disabilities, and are
> a critical part of the cascade. The word MAY should be replaced by

I agree that user style sheets are very beneficial to the user, but
typically this is true only on devices such as desktop computers that have a
keyboard etc. In fact, UAAG 1.0 explicitly recognizes this appropriate
targeting for itself, and states it clearly[2].

Additionally, it did not make sense to place such user interface
requirements on what essentially may be (and typically are) embedded systems
which allow for very little user customization in general.

This change from the respective conformance requirement in CSS2 was
explicitly made by the CSS Working Group for both the CSS Mobile Profile and
CSS TV Profile, for the same reasons.

Thanks again for your feedback, and I hope you will also help with feedback
and suggestions for the nascent CSS3 Voice efforts, and future (post 1.0)
versions of the CSS TV Profile.



Received on Friday, 14 June 2002 06:39:42 UTC

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