[2.4] Updated proposal

Draft of Guideline 2.4, 3 November 2004. This is an update to the
proposed wording [1] submitted to the list on 27 October. This draft
attempts to address concerns raised in the 28 October call. Major
differences from the 27 October proposal are:

*	Changes wording of the guideline itself. 
*	Adds a success criterion at level 1 (previous versions had no L1
success criteria). 
*	Adds a condition that triggers the requirement for a Table of
Contents; if accepted, this might resolve a comment submitted by Greg
Gay, issue #491. [2]. But it is still an arbitrary threshhold and that
may be problematic. 
*	Eliminates a proposed criterion about detailed views of complex
graphics. 
*	Offers new wording for the level 3 criterion about reading
order, and adds an Editor's note suggesting that the criterion be moved
to Principle 3. 

<proposed> 

Guideline 2.4. Provide tools to help users find content, orient
themselves within it, and navigate through it.


Level 1 success criteria for Guideline 2.4


1.	Structures within the content can be determined
programmatically. 

Editor's note:This is very close to the wording of Guideline 1.3 L1 SC 1
("Structures and relationships within the content can be determined
programmatically"). Several people who participated in the 28 October
call felt that there should be a Level 1 success criterion for this
guideline, and that it should be identical or nearly identical to 1.3 L1
SC1. There was some discussion about whether to use exactly the same
wording, or just link to 1.3 L1 SC1. But there was also some feeling
that the reference to "relationships" expressed in 1.3 L1 SC1 would not
be appropriate here. So the proposed wording is slightly different from
that in 1.3.


Level 2 success criteria for Guideline 2.4


1.	Documents that have five or more section headings and are
presented as a single perceivable unit include a Table of Contents with
links to important sections of the document. 

	Editor's note:This success criterion may become unnecessary if
the proposal to make UAAG 1.0 the baseline is adopted. User agents that
conform to UAAG 1.0, checkpoints 9.9 (Allow structured navigation
[Priority 2]) and 10.4 (Provide outline view [Priority 2]( could create
a Table of Contents automatically using structural markup within the
document. (There are extensions for Firefox that provide outline view,
and there are similar extensions/plug-ins for both IE and Mozilla.
However, the UAAG checkpoints referenced above are Priority 2, and we
have not yet discussed the level of conformance to UAAG 1.0 that would
be required in our baseline.

2.	There is more than one way to locate content, including but not
limited to link groups, a site map, site search or other navigation
mechanism. 
3.	Blocks of repeated material, such as navigation menus with 8 or
more links, are marked up so that they can be bypassed by people who use
assistive technology or who navigate via keyboard or keyboard interface.
[V] 

	Editor's note:General Techniques might include something about
satisfying this criterion through metadata, use of a future role
attribute, etc.


Guideline 2.4 L3


1.	When content is arranged in a sequence that affects its meaning,
that sequence can be determined programmatically. 

	Editor's note:This is an improvement upon the wording proposed
on 27 October, but it still needs work. The problem is how to specify
that it applies to content that is intended to appear as a sequence
without requiring a test for intention.

	Editor's note:The criterion about reading order would probably
be more appropriate under Principle 3: it could be argued that reading
order is irrelevant unless it affects the user's ability to understand
the content. This in itself is not necessarily an accessibility issue.
It becomes an accessibility issue if a user with a disability (such as a
visual or cognitive impairment) could not reliably derive a meaningful
reading order from the default presentation. If we want to retain this
criterion and keep it under 2.4, we need to craft wording that ties
reading order to users' ability to operate and use the content.

2.	The tab order follows relationships and sequences in the
content. 
3.	Images have structure that users can access. 
4.	Perceivable units have descriptive titles 
5.	Text is divided into paragraphs. 
6.	Documents are divided into hierarchical sections and subsections
that have descriptive titles. 

</proposed> <current> Guideline 2.4 Facilitate the ability of users to
orient themselves and move within the content. [level 2 guideline] Level
1 Success Criteria for Guideline 2.4 List of 1 items 1. No level 1
success criteria for this guideline. list end Level 2 Success Criteria
for Guideline 2.4 List of 2 items (contains 1 nested list) 1. In
documents greater than 50,000 words or sites larger than 50 perceived
pages, at least one of the following is provided. [V] Editorial Note:
What's a perceived page? What if it's a voice XML application? How does
it apply to Web applications? Why 50 and 50,000? List of 3 items nesting
level 1 A. hierarchical structure, B. table of contents (for pages) or
site map (for sites), C. alternate display order (for pages) or
alternate site navigation mechanisms (for sites). list end nesting level
1 2. Large blocks of material that are repeated on multiple pages, such
as navigation menus with more than 8 or more links, can be bypassed by
people who use screen readers or who navigate via keyboard or keyboard
interface. [V] list end Level 3 Success Criteria for Guideline 2.4 List
of 5 items (contains 1 nested list) 1. Information is provided that
would indicate at least one logical sequence in which to read a
document. [I] 2. Diagrams are constructed so that they have structure
that users can access. [I] 3. Logical tab order has been created. [I]
Editorial Note: "logical tab order" may not be testable. 4. Each page or
other resource that can be accessed separately and that supports a title
has a title that identifies the subject or purpose of the resource. [I]
Editorial Note: We need to define "accessed separately" to clarify that
what is being titled is a piece of content in its entirety vs.
individual elements or portions of the content. 5. There is a statement
associated with the content asserting that items from the following list
were considered: [V] List of 3 items nesting level 1 A. Breaking up text
into logical paragraphs, B. Dividing documents, especially very long
ones, into hierarchical sections and subsections with clear and
informative titles, C. Revealing important non-hierarchical
relationships, such as cross-references so that the relationships are
represented unambiguously in the markup or data model. Editorial Note:
Are there any others? list end nesting level 1 list end </current> 

[1]
http://lists.w3.org/Archives/Public/w3c-wai-gl/2004OctDec/0199.html#star
t

[2]
http://trace.wisc.edu/bugzilla_wcag/issuereports/navigation-mechanisms_i
ssues.php#491

 

"Good design is accessible design." 
John Slatin, Ph.D.
Director, Accessibility Institute
University of Texas at Austin
FAC 248C
1 University Station G9600
Austin, TX 78712
ph 512-495-4288, f 512-495-4524
email jslatin@mail.utexas.edu
web http://www.utexas.edu/research/accessibility/
<http://www.utexas.edu/research/accessibility/>