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SC 2.7.3

From: Simon Harper <simon.harper@manchester.ac.uk>
Date: Fri, 11 Mar 2011 11:24:16 +0000
Message-ID: <4D7A0660.6010203@manchester.ac.uk>
To: UAWG list <w3c-wai-ua@w3.org>
Continuing to chomping my way through 2.7 - here is sc 2.7.3 for your 
perusal, this SC already had text in it I'm just moving it into a form 
that is more in keeping with the others and polishing, or maybe 
tarnishing, it...

2.7.3 (former 4.7.4) Location in Hierarchy: The user can view the path 
of nodes leading from the root of any content hierarchy in which the 
structure and semantics are implied by presentation, as opposed to an 
explicit logical structure with defined semantics (such as the HTML5 
Canvas Element), or as a consequence of decentralized-extensibility 
(such as the HTML5 item / itemprop microdata elements), and only if the 
user agent keeps an internal model of the hierarchy that it does not 
expose via the DOM or some other accessibility mechanism. (Level A) .

Intent of Success Criterion 2.7.3 (former 4.7.4) :
Knowing where you are in a hierarchy makes it easier to understand and 
navigate information. Users who are perceiving the data linearly (such 
as audio speech synthesis) do not receive visual cues of the 
hierarchical information. Efficient navigation of hierarchical 
information reduces keystrokes for people for whom a key-press is 
time-consuming, tiring, or painful. For people with some cognitive 
disabilities, providing the clear hierarchy reduces cognitive effort and 
provides organization. For instance, a media player provides a 
hierarchical display of playlists, albums, artists and songs, etc. When 
the user selects an individual item, a breadcrumb of the categories is 
displayed, can be navigated and is available programmatically.

Examples of Success Criterion 2.7.3 (former 4.7.4) :
Jane works for a leading PR company and has been blind from birth. Her 
job requires her to do a significant amount of Web surfing in gossip and 
human interest magazine sites. However, in the charge towards HTML5 many 
of these sites are replacing standard html content with slick 'Canvas' 
designs. While the hierarchical information is present (otherwise her 
browser would not be able to render it) this is not available to Jane. 
This means that her assistive technology has no way of gaining access to 
the information. Jane needs a browser which, where present, makes the 
canvas hierarchy explicit and available to both herself and her 
assistive technology; just like it does for the page DOM.

Related Resources for Success Criterion 2.7.3 (former 4.7.4) :
UAAG 2.7.2 Access Relationships



Simon Harper
University of Manchester (UK)

Received on Friday, 11 March 2011 11:24:44 UTC

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