Understanding Success Criterion 1.3.1 [Info and Relationships]
1.3.1 Information and relationships conveyed through presentation can be programmatically determined or are available in text[begin delete], and notification of changes to these is available to user agents, including assistive technologies [2305] [end delete]. (Level A)
Intent of this Success Criterion
The intent of this success criterion is to ensure that information and relationships that are implied by visual or auditory formatting are preserved when the presentation format changes. For example, the presentation format changes when the content is read by a screen reader or when a user style sheet is substituted for the style sheet provided by the author.
Sighted users perceive structure through various visual cues — headings are often in a larger, bold font separated from paragraphs by blank lines; list items are preceded by a bullet and perhaps indented; paragraphs are separated by a blank line; items that share a common characteristic are organized into tabular rows and columns; form fields may be positioned as groups that share text labels; a different background color may be used to indicate that several items are related to each other; words that have special status are indicated by changing the font family and /or bolding, italicizing, or underlining them and so on.
Auditory cues may be used as well. For example, a chime might indicate the beginning of a new section; a change in voice pitch or speech rate may be used to emphasize important information or to indicate quoted text; etc.
When such relationships are perceivable to one set of users, those relationships can be made to be perceivable to all. One method of determining whether or not information has been properly provided to all users is to access the information serially in different modalities.
If links to glossary items are implemented using anchor elements (or the proper link element for the technology in use) and identified using a different font face, a screen reader user will hear that the item is a link when the glossary term is encountered even though they may not receive information about the change in font face. An on-line catalog may indicate prices using a larger font colored red. A screen reader or person who can not perceive red, still has the information about the price as long as it is preceded by the currency symbol.
Some technologies do not provide a means to programmatically determine some types of information and relationships. In that case then there should be a text description of the information and relationships. For instance, "all required fields are marked with an asterisk (*)". The text description should be near the information it is describing (when the page is linearized), such as in the parent element or in the adjacent element.
There may also be cases where it may be a judgment call about what information should appear in text and what would need to be directly associated, and it may be most appropriate to duplicate some information (for instance, in an HTML table, providing the summary both in the paragraph before the table and in the summary attribute of the table itself). However, wherever possible it is necessary for the information to be programatically determined rather than providing a text description before encountering the table.
[end add]Note: It is not required that color values be programmatically determined. The information conveyed by color cannot be adequately presented simply by exposing the value. Therefore, success criterion 1.4.1 addresses the specific case of color, rather than success criterion 1.3.1. [2202]
[end add]Specific Benefits of Success Criterion 1.3.1:
This success criterion helps people with different disabilities by allowing user agents to adapt content according to the needs of individual users.
Users who are blind (using a screen reader) benefit when information conveyed through color is also available in text (including text alternatives for images that use color to convey information).
Users who are deaf-blind using braille (text) refreshable displays may be unable to access color-dependent information.
Examples of Success Criterion 1.3.1
A form with required fields
A form contains several required fields. The labels for the required fields are displayed in red. In addition, at the end of each label is an asterisk character, *. The instructions for completing the form indicate that "all required fields are displayed in red and marked with an asterisk *", followed by an example.
A form that uses color and text to indicate required fields
A form contains both required and optional fields. Instructions at the top of the form explain that required fields are labeled with red text and also with an icon whose text alternative says, "Required." Both the red text and the icon are programmatically associated with the appropriate form fields so that assistive technology users can determine the required fields.
A bus schedule table where the headers for each cell can be programmatically determined
A bus schedule consists of a table with the bus stops listed vertically in the first column and the different buses listed horizontally across the first row. Each cell contains the time when the bus will be at that bus stop. The bus stop and bus cells are identified as headers for their corresponding row or column so that assistive technology can programmatically determine which bus and which bus stop are associated with the time in each cell.
A form where the labels for the checkboxes can be programmatically determined
In a form, the labels for each checkbox can be programmatically determined by assistive technology.
A text document
A simple text document is formatted with double blank lines before titles, asterisks to indicate list items and other standard formatting conventions so that its structure can be programmatically determined.
Techniques and Failures for Success Criterion 1.3.1 [Info and Relationships]
Each numbered item in this section represents a technique or combination of techniques that the WCAG Working Group deems sufficient for meeting this success criterion. The techniques listed only satisfy the success criterion if all of the WCAG 2.0 conformance requirements have been met.
Sufficient Techniques
Instructions: Select the situation below that matches your content. Each situation includes techniques or combinations of techniques that are known and documented to be sufficient for that situation.
Situation A: The technology provides semantic structure to make information and relationships conveyed through presentation programmatically determinable:
G115: Using semantic elements to mark up structure AND H49: Using semantic markup to mark emphasized or special text (HTML)
G117: Using text to convey information that is conveyed by variations in presentation of text
Separating information and structure from presentation to enable modification of presentation without altering content (future link)
Making information and relationships conveyed through presentation programmatically determinable using the following techniques:
H51: Using table markup to present tabular information (HTML)
H39: Using caption elements to associate data table captions with data tables (HTML)
H73: Using the summary attribute of the table element to give an overview of data tables (HTML)
H63: Using the scope attribute to associate header cells and data cells in data tables (HTML)
H43: Using id and headers attributes to associate data cells with header cells in data tables (HTML)
H44: Using label elements to associate text labels with form controls (HTML)
H65: Using the title attribute to identify form controls when the label element cannot be used (HTML)
H71: Providing a description for groups of form controls using fieldset and legend elements (HTML)
SCR21: Using functions of the Document Object Model (DOM) to add content to a page (Scripting)
Situation B: The technology in use does NOT provide the semantic structure to make the information and relationships conveyed through presentation programmatically determinable:
G117: Using text to convey information that is conveyed by variations in presentation of text
Making information and relationships conveyed through presentation programmatically determinable or available in text using the following techniques:
T1: Using standard text formatting conventions for paragraphs (TXT)
T2: Using standard text formatting conventions for lists (TXT)
T3: Using standard text formatting conventions for headings (TXT)
Presenting tabular information in plain text (future link)
Common Failures Identified by the Working Group
The following are common mistakes that are considered failures of Success Criterion 1.3.1 by the WCAG Working Group.
Additional Techniques (Advisory) for 1.3.1
Although not required for conformance, the following additional techniques should be considered in order to make content more accessible. Not all techniques can be used or would be effective in all situations.
Using CSS styles to change or enhance the presentation of structure (future link)
Using CSS rather than tables for page layout (future link)
Positioning labels to maximize predictability of relationships
Providing labels for all form controls that do not have implicit labels (future link)
Key Terms
- assistive technology (as used in this document)
- [begin add]
hardware and/or software that acts as a user agent, or along with a mainstream user agent, to provide services to meet the requirements of users with disabilities that go beyond those offered by the mainstream user agents [2140]
[end add][begin delete]provides services to meet the requirements of users with disabilities that go beyond those offered by the mainstream user agents. Such services include alternative presentations (e.g., as synthesized speech or magnified content), alternative input methods (e.g., voice), additional navigation or orientation mechanisms, and content transformations (e.g., to make tables more accessible), and
[begin change]may rely[end change] [begin delete]usually relies[end delete] on services (such as retrieving Web content and parsing markup) provided by one or more other mainstream user agents. Assistive technologies communicate data and messages with mainstream user agents by using and monitoring APIs
[begin add]Note 1: Services provided by assistive technology include alternative presentations (e.g., as synthesized speech or magnified content), alternative input methods (e.g., voice), additional navigation or orientation mechanisms, and content transformations (e.g., to make tables more accessible). [2140] [2270]
[end add][begin add]Note 2: Assistive technologies often communicate data and messages with mainstream user agents by using and monitoring APIs. [2270]
[end add][begin add]Note 3: The distinction between mainstream user agents and assistive technologies is not absolute. Many mainstream user agents provide some features to assist individuals with disabilities. The basic difference is that mainstream user agents target broad and diverse audiences that usually include people with and without disabilities. Assistive technologies target narrowly defined populations of users with specific disabilities. The assistance provided by an assistive technology is more specific and appropriate to the needs of its target users. The mainstream user agent may provide important services to assistive technologies like retrieving Web content from program objects or parsing markup into identifiable bundles. [2171]
[end add][begin delete]Note 4: In this definition, user agents are user agents in the general sense of the term. That is, any software that retrieves and presents Web content for users. The mainstream user agent may provide important services to assistive technologies like retrieving Web content from program objects or parsing markup into identifiable bundles.
[end delete][begin delete]Note 5: Mainstream user agents may also provide services directly that meet the requirements of users with disabilities.
[end delete][begin delete]Note 6: This definition is based on User Agent Accessibility Guidelines 1.0 Glossary.
[end delete]Example: Examples of assistive technologies that are important in the context of this document include the following:
screen magnifiers, and other visual reading assistants, which are used by people with visual, perceptual and physical print disabilities to change text font, size, spacing, color, synchronization with speech, etc. in order to improve the visual readability of rendered text and images;
screen readers, which are used by people who are blind to read textual information through synthesized speech or braille;
text-to-speech software, which is used by some people with cognitive, language, and learning disabilities to convert text into synthetic speech;
voice recognition software, which may be used by people who have some physical disabilities;
alternative keyboards, which are used by people with certain physical disabilities to simulate the keyboard[begin add] (including alternate keyboards that use headpointers, single switches, sip/puff and other special input devices.)[end add];
alternative pointing devices, which are used by people with certain physical disabilities to simulate mouse pointing and button activations.
- presentation
rendering of the content in a form to be perceived by users
- programmatically determined
determined by software from author-supplied data provided in a way that different user agents, including assistive technologies, can extract and present this information to users in different modalities
Example: Determined in a markup language from elements and attributes that are accessed directly by commonly available assistive technology.
Example: Determined from technology-specific data structures in a non-markup language and exposed to assistive technology via an accessibility API that is supported by commonly available assistive technology.
- relationships
meaningful associations between distinct pieces of content
- user agent
any software that retrieves and presents Web content for users
Example: Web browsers, media players, plug-ins, and other programs — including assistive technologies — that help in retrieving, rendering, and interacting with Web content.