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Re: PROPOSAL: Assistive Technology Checkpoints in the Guidelines

From: Charles McCathieNevile <charles@w3.org>
Date: Mon, 8 Feb 1999 14:39:46 -0500 (EST)
To: Jon Gunderson <jongund@staff.uiuc.edu>
cc: w3c-wai-ua@w3.org
Message-ID: <Pine.LNX.4.04.9902081425100.7435-100000@tux.w3.org>
As a preliminary comment, most of these things are covered under the
general principle 'provide device-independent access to all functionality
of the user agent' (which seems a lot like the current checkpoint 3.1.1)

The difference is that this proposal is splitting out particular functions
and requiring them (of particular browsers, in the current incarnation).

The issue of whether to implement the w3c recommendation for DOM is
separate.

Charles McCathieNevile

On Mon, 8 Feb 1999, Jon Gunderson wrote:

  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
  interface.
  
  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
  controls.
  
  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
  controls.
  
  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
  	http://www.als.uiuc.edu/InfoTechAccess
  

--Charles McCathieNevile            mailto:charles@w3.org
phone: +1 617 258 0992   http://purl.oclc.org/net/charles
W3C Web Accessibility Initiative    http://www.w3.org/WAI
MIT/LCS  -  545 Technology sq., Cambridge MA, 02139,  USA
Received on Monday, 8 February 1999 14:39:49 GMT

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