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PROPOSAL: Assistive Technology Checkpoints in the Guidelines

From: Jon Gunderson <jongund@staff.uiuc.edu>
Date: Mon, 08 Feb 1999 13:17:59 -0600
Message-Id: <199902081920.NAA02138@staff1.cso.uiuc.edu>
To: w3c-wai-ua@w3.org
Based on feedback from the group I think our current checkpoints related to
assistive technology compatibility need to be reconsidered for the
following reasons:

1. The current techniques for comaptibility read more like techniques than
statements of assistive technology needs.

2. DOM can only be considered as part of a solution for Desktop user agents
for the following reasons:

a. DOM does not provide any information or the emulation of controls for
the other parts of the user interface (i.e. controls, menus, staus lines,
dialpg boxes).  This information needs to come from a non-DOM source.  DOM
will never provide information or control about these parts of the user

b. DOM does not have a defined interoperable interface for use by external
programs.  Some group members say this is not a major issue (including
myself at times), but it is potentially a weak link if user agents running
on the same plateform use different methods to expose DOM.  Assistive
technology would then need to "know" where to look.  Also DOM does not have
any conventions for more simultaneous access to the DOM.  
How would DOM resolve manipulation requests from both the user agent and
the assistive technology? 
How would the user agent tell the AT that it changed something?

c. The use of DOM would require Assistive Technolgy to sub class the user
agent as a special technology and some assistive technology companies may
find this requirement to restraining as the primary mechanism for
accessibility, escpecially on MS-Windows plateforms that have accessibility
models based on active accessibility.  Denis Anson made a good point.  If
push this type of technique, it means that user with disabilities will need
to wait for AT developers to provide access to new implementations of DOM.
More general techniques like active accessibility, offer improved
timeliness to new releases of  user agents.

So I would like to suggest five checkpoints for people to think about,
criticize, modify and/or comment:

** The following checkpoints ae based on the assistive technologies point
of view **

Checkpoint 6.2.1 [Priority 1} Allow assistive technology to access
information about the current user interface controls (windows, menus,
toolbars, status bars, dialog boxes).

Primary techniques: Accessibility APIs or use of operating system standard

Checkpoint 6.2.2 [Priority 1} Allow assistive technology to simulate the
selection and activation of user interface and document controls (windows,
menus, toolbars, status bars, dialog boxes).

Primary techniques: Accessibility APIs or use of operating system standard

Checkpoint 6.2.3 [Priority 1] Allow assistive technologies to access
information about the current information being rendered by the user agent.

Primary techniques: Accessibility APIs that provide information on document 
rendering and/or DOM.

Checkpoint 6.2.4 [Priority 1] Allow accessibility features (accessibility
flags and interfaces. ) of the operating system to provide alternative
rendering information and user interfaces for the user agent.  

Checkpoint 6.2.5 [Priority 2] Allow assistive technology to change the
rendering of document information on the user agent.

Rationale: In some cases it maybe useful for the assistive technology to
change the rendering of a document.  For example for a person with certain
types of visual learning disabilities it maybe important to simplify the
rendering of the document and allow the person to use the mouse to point at
objects and have the contents of the object spoken to them.   It could also
be used for table linearization if the assistive technology felt that was
the best way for them to provide access to table information. 

Jon Gunderson, Ph.D., ATP
Coordinator of Assistive Communication and Information Technology
Division of Rehabilitation - Education Services
University of Illinois at Urbana/Champaign
1207 S. Oak Street
Champaign, IL 61820

Voice: 217-244-5870
Fax: 217-333-0248
E-mail: jongund@uiuc.edu
WWW:	http://www.staff.uiuc.edu/~jongund
Received on Monday, 8 February 1999 14:20:09 UTC

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