- From: eric hansen <ehansen@ets.org>
- Date: Wed, 19 May 1999 15:16:48 -0400 (EDT)
- To: w3c-wai-au@w3.org
I am convinced that the definitions of the priorities must focus on the
people with disabilities. There was a suggestion that the definition of
priorities use a term like "authors (including authors with disabilities)"
when referring to the impact of violating a checkpoint.
In this set of guidelines it is tempting to try to encompass a large set of
users, i.e., all authors or all users. But I strongly encourage resisting
the temptation. Our charter is to address disability access issues related
to authoring tools. If we try to evaluate the impact on users without
disabilities, we are out of our domain and our opinions have no more
credibility or authority than the opinions of others. We should not dilute
our influence by stepping over the bounds of our charter. As I have
indicate earlier, it is fine to tell why we think the document might be
helpful to nondisabled users (or "all users"), but the definitions of
priorities and other such core elements of the document must focus strictly
on people with disabilities. I believe that to have the priority
definitions refer to people other than "individuals with disabilities" or
"disability groups" will seriously dilute the influence and authority of
the document. I suggest that we stay keep adhering to the principle that
the priority level is determined by the impact on people with disabilities.
To illustrated, following is extracted from my 5/19/99 revision of the
4/30/99 WATG document.
1.2 Checkpoint priorities {EH:I-001:(Issue number added 5/18/99. It was
missing.)}
Each checkpoint in this document is assigned a priority level that is based
on the checkpoint's impact on people with disabilities. The specific
meanings of the priorities vary between sections 2 and
3.{EH:I-011. Separation of sections}
{EH:I-002:(Issue number added 5/18/99. It was missing.) Note separate
sections (2 and 3)}Section 2 focuses on ensuring that the _content_
produced by the authoring tool is accessible. Following are the meanings of
the priority levels for section 2:
· Priority 1: This checkpoint must be implemented by authoring tools
because violation of the checkpoint causes the content produced by the
authoring tool to be impossible to access by one or more disability groups.
· Priority 2: This checkpoint should be implemented by authoring tools
because violation of the checkpoint causes the content produced by the
authoring tool to be difficult to access by one or more disability groups.
· Priority 3: This checkpoint may be implemented by authoring tools because
violation of the checkpoint causes the content produced by the authoring
tool to be somewhat difficult to access by one or more disability groups.
{EH:I-012:5/19/99-15:09 hrs}The priority rating assigned to a section 2
checkpoint is based on the assumption that users of the content have
typical (or average) skill levels in accessing and using Web content. {EH:
I have ignored saying whether this is average for a disability group. I
think one should assume an average of a broader population, though I don't
think that it is necessarily worth stating.}
Section 3 focuses on ensuring that the _authoring tools themselves_ are
accessible. Following are the meanings of the priority levels for section
3:
· Priority 1: This checkpoint must be implemented by authoring tools
because violation of the checkpoint causes the authoring tool to be
impossible to access by one or more disability groups.
· Priority 2: This checkpoint should be implemented by authoring tools
because violation of the checkpoint causes the authoring tool to be
difficult to access by one or more disability groups.
· Priority 3: This checkpoint may be implemented by authoring tools because
violation of the checkpoint causes the authoring tool to be somewhat
difficult to access by one or more disability groups.
{EH:I-013:The priority rating assigned to a section 3 checkpoint is based
on the assumptions that:
· (1) {EH:I-014: Revised 5/19/99:}Users of the authoring tool have an skill
level that is typical of successful users of that type of authoring tool.
· (2) {EH:I-015:}Users employ the functionality of powerful intuitive
interfaces (e.g., _WYSIWYG [What You See Is What You Get]) instead of
less-intuitive (yet still powerful) interfaces (e.g., direct editing of
HTML codes with a text editor). Without this assumption, virtually no
checkpoint violation would be "impossible", since almost anything involving
data can be performed with a text editor, albeit with extreme difficulty.
Note that the priority rating system is not fully appropriate for authoring
tools that rely only on direct editing of Web pages through a text editor;
for such tools, authoring tends to be slower, but, as noted, virtually no
task is "impossible". {EH: Reference to "generations" is probably not
necessary: "Users generally employ third- or fourth-generation language
(e.g., _WYSIWYG_ editing){EH: Check on usage}or similar functionality of
the authoring tool instead of first- or second-generation languages (e.g.,
directed editing of HTML codes using a simple text editor). Note that the
priority rating system is not fully appropriate for authoring tools that
rely only on direct editing of Web pages through a text editor; for such
tools, authoring tends to be slower, but virtually no task is
"impossible".}
The priority ratings for both section 2 section 3 are based on the
assumptions that:
· (1) {EH:I-016:}Content produced is of typical variety (information,
education, entertainment, commerce).
· (2) {EH:I-017:}Estimates of impact take into account the contrast in
accessibility between consistent (pervasive) adherence and consistent
violation of the given checkpoint. This "consistency" assumption is
important to estimate the full impact. {EH: Note. A second, more subtle
aspect of this is the "contrast" assumption, which is becomes especially
important if one does not define a clear set of reference groups and begins
looking at "subgroups" such as "deaf nonreaders." The "difference"
assumption properly causes a checkpoint requiring visually-displayed text
(which is extremely helpful for deaf readers) to have an undefined impact
on deaf nonreaders, since there is no "contrast" in accessibility with or
without adherence to the checkpoint. (Both conditions are equally
innaccessible.)}
· (3) {EH:I-018:}User agents (both to access the content in section 2 and
as a typical component of authoring tools in section 3) are those available
(or soon to be available) commercially to members of the disability group.
· (4) {EH:I-019:}All priority ratings are based on a set of reference
groups at least as extensive as the following:
{EH:I-020: Insert the list of about 10-12 disability groups cited in the
WCAG document}
Furthermore, for both sections {EH:I-021:}:
1. Adherence to Priority 1 checkpoints is a basic requirement for
accessible design.
2. Adherence to Priority 2 checkpoints removes significant accessibility
barriers.
3. Adherence to Priority 3 checkpoints improves accessibility.
{EH: Without this statement, it will take a long time for people to figure
out the the meaning of the priority statements is so neatly partitioned by
section. Please correct me if the meaning are not so easily partitioned
between sections as I have indicated.}
=============================
Eric G. Hansen, Ph.D.
Development Scientist
Educational Testing Service
ETS 12-R
Rosedale Road
Princeton, NJ 08541
(W) 609-734-5615
(Fax) 609-734-1090
E-mail: ehansen@ets.org
Received on Wednesday, 19 May 1999 15:35:02 UTC