Guide to Guideline 2, Level 1, Success Criterion 1

Major sections of this page

• Understanding this Success Criterion
• Techniques for meeting this Success Criterion
• Benefits and Examples

Success criterion: What WCAG 2.0 requires

Guideline 2.4 Level 1 SC 1: Structures and relationships within the content can be programmatically determined.

Understanding this Success Criterion

Key terms and important concepts

• Structure: a classification of parts of content into logical categories such as grammatical parts of speech, sections of a document, or components of an object represented by a graphic.
• Relationships: the way the structural components of content are organized in relation to each other.
• Programatically Determined: can be determined by the machine using standard methods for the technology that do not rely on heuristics.

Intent of this success criterion

When structure and relationships can be programatically determined, browsers and assistive technologies can explictly represent this information in a manner best for the user. This allows software to provide support facilities for navigation and comprehension when the user is unable to infer this from the graphical presentation.

Applicability: When does this Success Criterion Apply?

This success criterion is applicable when meaning of content is dependent on or enhanced by logical structure. This applies not only to text but the components of images, multimedia, and interactivity.

Additional details

• Benefits of this Success Criterion
• Examples of this Success Criterion

Techniques to meet this Success Criterion

Technology-Independent techniques for this Success Criterion

{For this SC, I'm not sure what I would provide beyond the definitions and examples here.}

Technology-Specific Techniques for this Success Criterion

{No Techniques defined yet. It would be possible to provide a bushel of techniques defining every thing that might be marked up semantically, but I'm not sure that will be useful in this context. The most that seems worthwhile would be a list of the technologies for which we provide techniquess, as follows.}

• HTML Techniques for 2.4.1.1
• SMIL Techniques for 2.4.1.1
• SVG Techniques for 2.4.1.1
• {No CSS Techniques - perhaps it's useful to say so in so many words here}
• {Ibid for Script Techniques}

Advisory techniques: going beyond this Success Criterion

{Not sure what to put here - either everything or nothing. At least in HTML, we have a bunch of techniques that just say things like "if you're using paragraphs, mark them as paragraphs". Those techniques could go here, but that would leave nothing for the previous section.}

Benefits and Examples

Benefits: How this Success Criterion Helps People with Disabilities

• 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, headers, 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 header to header to get an overview or to more quickly "skim" to the section they are interested in.
• 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.
• Readers with low vision can sometimes (depending on display technology) change how chapter titles and headers are displayed to make them more visible and easier to use when skimming the document.
• Individuals with cognitive disabilities may find it easier to ask for what they want than to deduce its location from categorical choices.
• 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.

Examples of this Success Criterion

Lexical structure

Text is usually organized into paragraphs, and other lexical units may be employed as well, such as lists, tables, quotes, headings, emphasis, etc. These units are identified explicitly using features of the technology, allowing users to search for particular types of content, skip to the next list or paragraph easily, or interpret a two-dimensional table.

Book structure

Identifying chapters in the structure of a book is appropriate and accepted way of labeling the structure. Within the chapters, headings identify (label) changes in context and highlight ideas contained in the following text. Subtle 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.

Data table

Groups of rows or columns are labeled with headers, and the relationship of data cells to header cells is identified.

Related resources

{We should link to resources that describe what the heck semantic and structural markup is to users who don't think in those terms. I couldn't find anything on a quick search of the W3C site but I would expect to find stuff in the Semantic Web, HTML, and XML areas at least. There should be external resources, some accessibility focused but hopefully not all.}