[2.4] Updated proposal for GL 2.4

Guideline 2.4: Proposed Wording for WCAG 2.0, Nov. 3 2004
 
Draft of Guideline 2.4, 15 November 2004. This is an update to the prior
proposals submitted to the list on 27 October [1] and 3 November [2].
This
draft attempts to address concerns raised in the 28 October call and in
Jason White's [3]response to the 3 November proposal.
List of 1 items
* 
list end
<proposed>
 
Guideline 2.4. Provide methods to help users find content, orient
themselves within it, and navigate through it.
 
Level 1 success criteria for Guideline 2.4
List of 1 items
1. Structures and relationships within the content can be determined
programmatically.
list end
 
Editor's note:This is identical 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. There
was also some feeling that the reference to "relationships" expressed in
1.3 L1 SC1 would not be appropriate here. Since the only response to the
wording
proposed on 3 November was a strong comment from Jason that the this SC
should be identical to 1.3 L1 SC1, the wording of 1.3 L1 SC1 is used
here as well.
 
Level 2 success criteria for Guideline 2.4
List of 3 items
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 the content of each delivery
unit, 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 and document
headers, 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.
list end
 
Guideline 2.4 L3
List of 6 items
1. When content is arranged in a sequence that affects its meaning, that
sequence can be determined programmatically.
 
Editor's note:The problem is how to specify that this SC applies to
content that is intended to appear as a sequence without requiring a
test for intention.
It has been suggested that reading order is already covered by the
requirement in 1.3 to make structures and relationships within the
content programmatically
determinable. If the Working Group and other readers share this view,
this could be deleted as a separate SC and the accompanying General
Technique could
be moved under 1.3.
 
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. Reading
order 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.
It is not necessarily true that merely exposing structure to the user
agent is sufficient to indicate a plausible reading order. The example
for the General
Technique about reading order is designed to highlight this issue.
2. When a page or other perceivable unit is navigated sequentially,
elements receive focus in an order that 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.
list end
 
Editor's note:This success criterion is also related to Guideline 1.3 L1
SC1, as follows: if graphical content has structure, it satisfies
Guideline 2.4
L3 SC2. If graphical content satisfies Guideline 2.4 L3 SC 2, it must
also satisfy Guideline 1.3 L1 SC1 by exposing that structure to user
agents. Thus
images do not have to include structural markup in order to satisfy
Guideline 1.3 L1 SC1. But if the image does include structure, that
markup must be
exposed to user agents, including assistive technology, in order to
satisfy Guideline 1.3 L1 SC2.
</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
 
[3]
http://lists.w3.org/Archives/Public/w3c-wai-gl/2004OctDec/0262.html#star
t
 

"Good design is accessible design."

Dr. John M. Slatin, Director 
Accessibility Institute
University of Texas at Austin 
FAC 248C 
1 University Station G9600 
Austin, TX 78712 
ph 512-495-4288, fax 512-495-4524 
email jslatin@mail.utexas.edu 
Web  <http://www.ital.utexas.edu/>
http://www.utexas.edu/research/accessibility