Are the media controls of embedded video player appropriate for
partial conformance in the first place?
"Statement of Partial Conformance - Third Party Content" in WCAG 2.0 states:
- "Sometimes, Web pages are created that will later have additional
content added to them. For example, an email program, a blog, an
article that allows users to add comments, or applications supporting
user-contributed content."
- "it is not possible to know at the time of original posting what
the uncontrolled content of the pages will be."
The media controls are not "additional content" added to the web page.
They already exist at the time of original posting. And it is possible
for the author to know how the media controls would be presented to
users at the time of original posting.
Is partial conformance also appropriate for the uncontrolled content
which won't "later have additional content"?
The media controls may be updated without notice, but it doesn't mean
that they will be added after the time of original posting.
Email messages in "an email program", articles on "a blog", user's
comments in "an article that allows users to add comments" and
user-contributed content in "applications supporting user-contributed
content" doesn't exist at the time of original posting and will be
added later. But the media controls exist at the time of original
posting. This is the difference and we thought that the media controls
are not appropriate for partial conformance in the first place.
Additional clarification on this point will also be very helpful and
appreciated.
See http://lists.w3.org/Archives/Public/w3c-wai-gl/2010OctDec/0024.html:
First, we will assume that the video player is web content, that is,
it is implemented in a scripting language rather than as a user agent.
In this case, the video player, including its controls, must meet WCAG
requirements.
If it were not the case that the video player could be updated
automatically, without action or approval by the web site author, it
would definitely not be third party content. Authors often use
libraries provided by third parties, for example, but that does not
make the content appropriate for partial conformance. In this case,
either the video player conformed to WCAG or it did not. If it did
not, then the page containing the video would not conform.
Since your question stated that the video player could be updated
automatically without approval from the web site author, it becomes
more like the content of a feed that changes very slowly. This would
be the reason that partial conformance might be used if the web site
author was not prepared to repair any accessibility problems
introduced by an updated video player.
See http://lists.w3.org/Archives/Public/w3c-wai-gl/2010OctDec/0028.html:
Thank you very much for your reply.
> First, we will assume that the video player is web content, that is,
> it is implemented in a scripting language rather than as a user agent.
> In this case, the video player, including its controls, must meet WCAG
> requirements.
OK.
> If it were not the case that the video player could be updated
> automatically, without action or approval by the web site author, it
> would definitely not be third party content. Authors often use
> libraries provided by third parties, for example, but that does not
> make the content appropriate for partial conformance. In this case,
> either the video player conformed to WCAG or it did not. If it did
> not, then the page containing the video would not conform.
OK.
> Since your question stated that the video player could be updated
> automatically without approval from the web site author, it becomes
> more like the content of a feed that changes very slowly. This would
> be the reason that partial conformance might be used if the web site
> author was not prepared to repair any accessibility problems
> introduced by an updated video player.
Here is a question I asked:
>> Is partial conformance also appropriate for the uncontrolled content
>> which won't "later have additional content"?
>> The media controls may be updated without notice, but it doesn't mean
>> that they will be added after the time of original posting.
Do you mean that WG's answer is "Yes"?
Our understanding is that web pages which WON'T later have additional
content is not applicable to the partial conformance in the first
place. It doesn't matter whether it may be updated without notice or
not. Because the examples such as "an email program", "a blog", and
"an article that allows users to add comments" are web pages which
WILL later have additional content.
If the answer is yes, the description in "Statement of Partial
Conformance - Third Party Content" is confusing. I think WCAG WG needs
to add the clarification on this issue to "Understanding WCAG 2.0".
See http://lists.w3.org/Archives/Public/w3c-wai-gl/2010OctDec/0032.html:
> Here is a question I asked:
>>> Is partial conformance also appropriate for the uncontrolled content
>>> which won't "later have additional content"?
>>> The media controls may be updated without notice, but it doesn't mean
>>> that they will be added after the time of original posting.
>
> Do you mean that WG's answer is "Yes"?
The WG's answer is "Yes".
>
> Our understanding is that web pages which WON'T later have additional
> content is not applicable to the partial conformance in the first
> place. It doesn't matter whether it may be updated without notice or
> not. Because the examples such as "an email program", "a blog", and
> "an article that allows users to add comments" are web pages which
> WILL later have additional content.
The description of the Statement of Partial Conformance also includes:
"Another example would be a page, such as a portal or news site,
composed of content aggregated from multiple contributors, or sites
that automatically insert content from other sources over time, such
as when advertisements are inserted dynamically."
The video player changing is similar to the advertisements changing.
This is not additional content, but it is changing content, and the
changed content is not under the control of the web page author
(although the author is responsible for deciding to include this
changing content).
>
> If the answer is yes, the description in "Statement of Partial
> Conformance - Third Party Content" is confusing. I think WCAG WG needs
> to add the clarification on this issue to "Understanding WCAG 2.0".
Can you suggest how we might clarify this issue?
See http://lists.w3.org/Archives/Public/w3c-wai-gl/2010OctDec/0050.html:
> The video player changing is similar to the advertisements changing.
> This is not additional content, but it is changing content, and the
> changed content is not under the control of the web page author
> (although the author is responsible for deciding to include this
> changing content).
The advertisements don't exist at the time of original posting. On the
other hand, the video player's controls do exist at the time of
original posting. This is the big difference.
>> If the answer is yes, the description in "Statement of Partial
>> Conformance - Third Party Content" is confusing. I think WCAG WG needs
>> to add the clarification on this issue to "Understanding WCAG 2.0".
>
> Can you suggest how we might clarify this issue?
Understanding should have the example of video player's controls that
the author has NO control of when it is updated. Many web pages embed
video players to provide synchronized media on the pages. This is very
important issue.
First of all, WAIC would like to get the official response from WCAG
working group. I'll be able to suggest the specific description based
on it.