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RE: Action Item: Investigate wording for possible third class agent for conformance section

From: Denis Anson <danson@miseri.edu>
Date: Tue, 31 Aug 1999 08:40:12 -0400
To: <schwer@us.ibm.com>, "Jon Gunderson" <jongund@staff.uiuc.edu>
Cc: <w3c-wai-ua@w3.org>

This proposal would be fine were it not for the fact that people with a
primary disability (such as blindness) sometimes also have a secondary
disability, such as physical movement restrictions, that must also be
accommodated.  If a targeted user agent provides only native conformance for
the issues that are considered to be pertinent to that disability (or more
appropriately, functional level), then it may not support the adaptations
required for the secondary disability.

Primarily, there are two components of access: input and output.  Most of
the targeted user agents are built around adaptations of output to a
different format: Braille or voice, for example.  Rendering video with
captioning deals with auditory output.  But even those with output
restrictions can have input restrictions, such that they cannot use the
standard keyboard/mouse interface, and must use an alternative input method.
All user agents should support external assistive technologies so that both
input and output can be modified as needed.

Denis Anson

-----Original Message-----
From: w3c-wai-ua-request@w3.org [mailto:w3c-wai-ua-request@w3.org]On
Behalf Of schwer@us.ibm.com
Sent: Monday, August 30, 1999 4:47 PM
To: Jon Gunderson
Cc: w3c-wai-ua@w3.org
Subject: Re: Action Item: Investigate wording for possible third class
agent for conformance section


After considerable thought on this on really believe section
needs to define a third class of agent called a "Targetted Agent." Targetted
agents like Home Page Reader and PWWebSpeak are user agents that are
to a specific disabilities group or groups. They are not designed to work
or provide access to features that an unrelated asssitive technology should
need. In particular, the definition of "Native support" required:

"for dependend user agents states that Native support does not preclude more
extensive support for accessibility by dependent user agents, so user agents
must still make information available through programming interfaces."

This means that if a targetted agent renders a document visually it needs to
support a DOM and expose all the API to another assistive technology for the
purposes of enabling access by different user agent technologies or
groups not intended by the targetted agent. When doing our Home Page Reader
Evaluation and when assessing future Home Page Reader product requirements
found numerous conformance checkpoints that were non-applicable for the

To change the wording in section 3.1 I would suggest the following:

The terms "must", "should", and "may" (and related terms) are used in this
document in accordance with RFC 2119 ([RFC2119]).

To promote interoperability between graphical desktop user agents and
user agents and between graphical desktop user agents and targetted agents
conformance to this document is expressed in terms of these three types of

Conformance for graphical desktop browsers

In order to conform as a graphical desktop browser, the user agent must
all the checkpoints (for a chosen conformance level) that apply to graphical
desktop browsers and do so natively.

Even for those checkpoints that must be satisfied natively, graphical
browsers should make information available to other software through
interfaces (e.g., specialized dependent user agents may provide a better
solution to a problem than a graphical desktop browser).

Conformance for dependent user agents
In order to conform as a dependent user agent, the user agent must satisfy
the checkpoints (for a chosen conformance level) that apply to dependent
agents and do so natively.

Conformance for targetted agents

In order to conform as a targetted agent, the user must satisfy all the
checkpoints (for a chosen conformance level) that apply to targetted agents.
Targetted agents are graphical desktop browsers targetted to a specific

The difficulty here will be deciding what checkpoints apply to what
Does such a list exist?


Rich Schwerdtfeger
Lead Architect, IBM Special Needs Systems
EMail/web: schwer@us.ibm.com http://www.austin.ibm.com/sns/rich.htm

"Two roads diverged in a wood, and I -
I took the one less traveled by, and that has made all the difference.",
Received on Tuesday, 31 August 1999 08:36:51 UTC

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