Proposed revision to applicability provision from Ian Jacobs on 2001-01-05 (w3c-wai-ua@w3.org from January to March 2001) (original) (raw)

Hello,

Section 3.3 of the 29 December draft [1] includes the following applicability provision:

"The checkpoint requires control of content properties (e.g., video or animation rate) that the subject of the claim cannot control (e.g., the format does not allow it) or does not recognize (e.g., because the property is controlled by a script in a manner that the subject of the claim cannot recognize)."

Recall that this applicability provision is here to cover cases such as the following:

Captions are "burned" into video.
Streamed content that may not be rewindable
Information embedded in scripts.

Al raised some concerns about this provision (issue 357), and I got an action item at the AOL ftf meeting to proposal a revision [2].

In discussions with Al, it became apparent that there might be two ways to interpret "the subject cannot control" properties of a format:

The format forbids it (e.g., if you do this, you don't conform).
The format doesn't enable it (e.g., due to limits in the format).

I therefore propose to modify the applicability provision to state more clearly that point (2) is intended:

"The checkpoint requires control of a content property that the subject cannot recognize because of how the content has been encoded in a particular format. Some examples of this include: captioning information that is "burned" into a video presentation and cannot be recognized as captions per se, streamed content that cannot be fast advanced or reversed, information or relationships embedded in scripts in a manner that cannot be recognized.

This wording is consistent with the model that the user agent is responsible for what is encoded in the format (which may be less than what the author knows about the content).

[1] http://www.w3.org/WAI/UA/WD-UAAG10-20001229/#applicable [2] http://www.w3.org/WAI/UA/2000/11/minutes-20001116#issue-357

Ian Jacobs (jacobs@w3.org) http://www.w3.org/People/Jacobs Tel: +1 831 457-2842 Cell: +1 917 450-8783

Received on Friday, 5 January 2001 14:41:57 UTC