Proposal

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

@@ John, Michael, Yvette wonder if orientation isn't covered by navigation already, because the major function of orientation is knowing where you ended up or where you're going to

Level 1 Success Criteria for Guideline 2.4

Structures and relationships within the content can be programmatically determined. [I]
Note: Conforming to the first level 1 criterion in '' Guideline 1.3 Ensure that information, functionality, and structure are separable from presentation.'' also addresses this success criterion.
Editorial Note: The working group seeks input about the overlap of criterion for guidelines 1.3 and 2.4.
When content is arranged in a sequence that affects its meaning, that sequence can be determined programmatically. [I]
Editorial Note: The problem is how to specify that this criterion 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 to guideline 1.3.
Editorial Note: The criterion about reading order may 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.
- @@ Jason suggests that this belongs under 1.3 and is redundant with 1.3 level 1
- John suggested: The integrity or structure of each authored unit remains intact whenever a collection of authored units is assembled into a delivery unit and whenever a delivery unit is transformed into a perceivable unit.
For each programmatic reference to another delivery unit, a title or description of that delivery unit can be programatically determined.
- @@ YPH This item overlaps with 3.2 level 3 SC 6: "The destination of each link is identified through words or phrases that either occur in the link or can be programmatically determined." However, this SC also coveres title-attributes for frames and similar references while the 3.2 SC is specific to links.

Level 2 Success Criteria for Guideline 2.4

Documents that have five or more section headings and are presented as a single delivery unit include a table of contents with links to important sections of the document. [V]
- @@ Andi's proposed rewording Documents that have five or more section headings and are presented as a single delivery unit include a table of contents with links each section heading of the document.
- @@ John proposes removing this SC and covering TOC uner navigation methods. John later reconsidered because this SC deals with navigation within a delivery unit while the SC under level 2 covers navigation between delivery units.
- @@ John, Michael and Yvette propose to delete this SC.
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. [V]
- @@ John proposes: There is more than one way to locate the content of each delivery unit, including but not limited to link groups, a table of contents, a site map, site search or other navigation mechanism. [V]
Blocks of repeated material are implemented so that they can be bypassed by people who use assistive technology or who navigate via keyboard or keyboard interface. [V]
Editorial Note: General Techniques might include something about satisfying this criterion through metadata, use of a future role attribute, etc.
- @@ Andi's proposed rewording Blocks of material that are duplicated on the delivery units of a Web site domain are implemented so that they can be bypassed by people who use assistive technology or who navigate via keyboard or keyboard interface.
- @@ John's suggested revision: Blocks of material that are repeated on multiple perceivable units in the same domain are implemented so that they can be bypassed by people who use assistive technology or who navigate via keyboard or keyboard interface.
- @@ John, Michael and Yvette propose: Blocks of material that are repeated on multiple perceivable units are implemented so that they can be bypassed by people who use assistive technology or who navigate via keyboard or keyboard interface.

Level 3 Success Criteria for Guideline 2.4

When a page or other delivery unit is navigated sequentially, elements receive focus in an order that follows relationships and sequences in the content. [I]
Images have structure that users can access. [I]
- @@ John, Michael and Yvette feel this SC is too restrictive in its present form (since it would essentially allow only SVG) but is worth reworking (whreas the impact analysis proposes killing the SC altogether). The SC should be recast in terms of making graphical content navigable-e.g., Google Maps, MapQuest, etc. By rewriting the requirement in terms of a functional outcome (not done yet), we could *allow* but not require SVG while also allowing other methods, including Javascript, that are well entrenched in contemporary practice.
Delivery units have descriptive titles [I]
Text is divided into paragraphs. [V]
- @@ Andi suggests replacing "divided" with "organized"
Documents are divided into hierarchical sections and subsections that have descriptive titles. [V]

Guideline 2.4 (navigation-mechanisms) Issues

Who Benefits from Guideline 2.4 (Informative)

When the logical structure is provided in markup or a data model,
- Users with physical disabilities can use structure to more easily jump between paragraphs, chapters, sections etc.
- Users with cognitive disabilities can use structure (chapter titles, headings, etc.) to provide more context for the text that follows them. They also provide warning of a change in context and reorient the user to the new focus.
- Users with blindness or low vision can jump from heading to heading to get an overview or to more quickly "skim" to the section they are interested in.
- Readers with low vision can sometimes (depending on display technology) change how chapter titles and headings are displayed to make them more visible and easier to use when skimming the document.
- the content can be presented on a variety of devices because the device software can choose only those elements of the content that it is able to display and display them in the most effective way for that device.
Providing different navigation mechanisms can provide a better match between different people's skills, background knowledge, visual vs. text orientation, and the type of information they are seeking at the moment.
Individuals with cognitive disabilities may find it easier to ask for what they want than to deduce its location from categorical choices.
Individuals with low vision or blindness may find search techniques that fetch everything that relates to a topic of interest to be easier than techniques that require them to scan lists or content for the items.
Presentation that emphasizes structure:
- enables users with cognitive and visual disabilities to orient themselves within the content,
- enables all users to move quickly through the content and notice major content divisions
- enables all users, but particularly users with visual or cognitive disabilities to focus on important content,
- enables all users, but particularly users with visual or cognitive disabilities to distinguish the different types of content.

Examples of Guideline 2.4 (Informative)

Example 1: documentation for a product.
Identifying chapters in the structure of a book is appropriate and accepted use of labeling the structure. Within the chapters, headings identify (label) changes in context and highlight ideas contained in the following text. Differences between the appearance of the chapter title and the section headings helps the user understand the hierarchy and relationship between the title and headings. The difference might be font size and margin indentation when presented visually, and spoken in a different voice or preceded by a sound when presented auditorily.
Example 2: a scalable image of a map.
The content contains an image of a map. The author chooses an image technology that allows him to define the relationships between the different parts of the image. States or provinces are grouped into a 'Country'. Countries are grouped into a 'Continent'.
Example 3: user interface.
User interface controls are divided into organized groups.
Example 4: a data table.
Groups of rows or columns are labeled with headings.
Example 5: an audio presentation.
An aural style sheet defines a different voice to read the headings in the document. This difference might be in pitch, volume or in tone, for example by using a louder, more formal voice. This way, the user can easily hear the difference between a heading and the main text.
Example 6: an online newsletter.
The main content area of an online newsletter uses a layout that features two columns of text. as There is a "pullquote" in the center of the screen - that is, a phrase taken from the article and displayed in a larger font to emphasize an important idea. The pullquote is shown over a shaded background and there is a border around it. Visually, the pullquote overlaps portions of both columns in the text. The page also includes a sidebar with a list of phone numbers. The visual layout does not require that the content be read in a certain order. However, it is important that people who use screen readers or text-only displays be able to read the content in a sequence that makes sense. Thus, the pullquote and the sidebar are clearly distinguished from the text in the left and right columns so that user agents can render the content separately.
Example 7: a website with many articles.
A website that consist of a large number of articles offers different ways to locate the articles. A search engine is provided so the user can search the text of the articles. Also, a list of categories is provided so the user can select a category and browse through all the articles in that category. For this purpose, the authors have assigned categories to each article in the website. Together with the article, a list of 'related articles' is displayed. This list consists of links to articles that are about the same topic as the current article.

Appendix A Glossary

document: A document is a writing that contains information.

May 2005 Guideline 1.3 Proposal (last edited 2005-07-25 13:47:56 by WendyChisholm)