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Implementation details for 3.1.1 (Identify Presence of Alternative Content)

From: Greg Lowney <gcl-0039@access-research.org>
Date: Thu, 25 Feb 2010 17:54:17 -0600
Message-ID: <4B870DA9.2090206@access-research.org>
To: W3 UA list <w3c-wai-ua@w3.org>
This includes a major proposed rewording of 3.1.1.

Previous wording:

3.1.1 Notification of Alternative Content: Provide a global option for 
the user to receive cues in the presence of alternatives to rendered 
content (e.g. visual icons rendered in proximity of content which has 
short text alternatives, long descriptions, or captions).

Proposed new wording:

3.1.1 Identify Presence of Alternative Content: The user has the ability 
to have indicators rendered along with rendered elements that have 
alternative content (e.g. visual icons rendered in proximity of content 
which has short text alternatives, long descriptions, or captions). 
(Level A)

(Also, we are tempted to include the sentence "When the indicator is 
inserted into content in such a way as to change its dimensions, the 
user has a global option to specify how layout/reflow of the document 
should be handled." but think this will be handled by a separate success 
criterion.)

    * Intent of Success Criterion 3.1.1:

When the author provided alternative content, it is wasted if the user 
cannot find it. Thus it becomes the responsibility of the user agent to 
make the presence of alternative content evident to the user. The user 
should not have to hunt and examine every time to see if it includes 
such content, as such searching can be time-consuming, especially for 
users whose disability makes input difficult, tiring, or painful. The 
user should be able to easily identify which items have alternative 
content, rather than being merely informed that alternative content is 
somewhere in the view.

    * Examples of Success Criterion 3.1.1:

          o Distinct visual icons are rendered in proximity of content 
which has short text alternatives, long descriptions, captions. If the 
icon forces the text to extend beyond a fixed size container the user 
agent handles this using its global preference settings to determine 
whether it expands the container, provides scroll bars, or truncates the 
content.

          o When rendering a Web page using synthesized speech, the 
browser generates an audible tone to signify the word being read is an 
acronym, and the user can press the * key to hear the expansion. When 
the phrase being read is the Alt text for an image, another tone 
indicates that the user can press + to hear the longdesc.

          o A button is displayed beneath the playing video to indicate 
that captions are available and to let the user toggle their display.

    * Related Resources for Success Criterion 3.1.1:

          o (Refer to the SC about handling layout/reflow options.)


(From Jim and Greg)
Received on Thursday, 25 February 2010 23:54:45 GMT

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