Understanding Guideline 1.1:
Provide text alternatives for any non-text content so that it can be changed into other forms people need such as large print, braille, speech, symbols or simpler language
Intent of Guideline 1.1
The purpose of this guideline is to ensure that all non-text content is also available in text. "Text" refers to electronic text, not an image of text. Electronic text has the unique advantage that it can be rendered visually, auditorially, tactilely, or by any combination. As a result, information rendered in electronic text can be presented in whatever form best meets the needs of the user. It can also be easily enlarged, spoken in a voice that is easy to understand, or rendered in whatever tactile form best meets the needs of a user.
Advisory Techniques for Guideline 1.1 (not success criteria specific)
Specific techniques for meeting each success criterion for this guideline are listed in the understanding sections for each success criterion (listed below). If there are techniques, however, for addressing this guideline that do not fall under any of the success criteria, they are listed here. These techniques are not required or sufficient for meeting any success criteria, but can make certain types of Web content more accessible to more people.
- All advisory techniques for this guideline relate to specific success criteria and are listed below.
Understanding Success Criterion 1.1.1 (Non-text Content)
1.1.1 All non-text content has a text alternative that presents equivalent information, except for the situations listed below.
[LC-956]
[LC-1281]
[LC-1524]
(Level A)
Controls-Input: If non-text content is a control or accepts user input, then it has a name that describes its purpose. (See also Guideline 4.1.)
[LC-738]
Media, Test, Sensory: If non-text content is multimedia
,
live audio-only or live video-only content, a test or exercise that must be presented in non-text format
[LC-1506]
, or primarily intended to create a specific sensory experience
, then text alternatives at least identify the non-text content with a descriptive text label. (For multimedia, see also Guideline 1.2.)
[LC-801]
CAPTCHA: If the purpose of non-text content is to confirm that content is being accessed by a person rather than a computer, then
[LC-738]
[LC-1282]
text alternatives that identify and describe the purpose of the non-text content are provided and alternative forms in different modalities are provided to accommodate different
[LC-800]
[LC-1155]
disabilities.
Decoration, Formatting, Invisible: If non-text content is pure decoration, or used only for visual formatting, or if it is not presented to users, then
[LC-738]
it is implemented such that it can be ignored by assistive technology.
Key Terms
- non-text content
any content that is not a sequence of characters that can be programmatically determined or where the sequence is not expressing something in human language
[LC-954]
Note: This includes ASCII Art (which is a pattern of characters) and leetspeak (which is character substitution).
[LC-796]
- text alternative
programmatically determined text that is used in place of non-text content, or text that is used in addition to non-text content and referred to from the programmatically determined text
Example: An image of a chart is described in text in the paragraph after the chart. The short text-alternative for the chart indicates that a description follows.
[LC-1507]
- name
text by which software can identify a component within Web content to the user
Note 1:
The name may be hidden and only exposed by assistive technology, whereas a label is presented to all users.
In many (but not all) cases, the label and the name are the same.
Note 2:
This is unrelated to the name attribute in HTML.
- multimedia
audio or video synchronized with another
format for presenting information and/or with time-based interactive components
[LC-1499]
- live audio-only
A time-based live presentation that contains only audio (no video and no interaction)
- live video-only
A time-based live presentation that contains only video (no audio and no interaction)
- must be presented in non-text format
would be invalid if presented in text
[LC-1506]
Example: Color blindness test, hearing test, vision exercise, spelling test.
- specific sensory experience
a sensory experience that is not purely decorative and does not primarily convey important information or perform a function
Example:
Examples include a performance of a flute solo, works of visual art etc.
[LC-1189]
- label
text
or other component with a text alternative
that is presented to a user to identify a component within Web content
- CAPTCHA
initialism for "Completely Automated Public Turing test to tell Computers and Humans Apart"
Note 1:
CAPTCHA tests often involve asking the user to type in text that is displayed in an obscured image or audio file.
Note 2:
A Turing test is any system of tests designed to differentiate a human from a computer. It is named after famed computer scientist Alan Turing. The term was coined by researchers at Carnegie Mellon University. [CAPTCHA]
- pure decoration
serving only an aesthetic purpose, providing no information, and having no functionality
Note: Text is only purely decorative if the words can be rearranged or substituted without changing their purpose.
Example: The cover page of a dictionary has random words in very light text in the background.
- Assistive technology (as used in this document
[LC-732]
)
a user agent that both:
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
[LC-1178]
usually relies 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
Note 1:
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.
[LC-732]
Note 2:
Mainstream user agents may also provide services directly that meet the requirements of users with disabilities.
[LC-732]
Note 3:
This definition is based on User Agent Accessibility Guidelines 1.0 Glossary.
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
[LC-604]
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;
alternative pointing devices, which are used by people with certain physical disabilities to simulate mouse pointing and button activations.
Intent of this Success Criterion
The intent of this success criterion is to make information conveyed by non-text content accessible through the use of a text alternative. Text alternatives are a primary way for making information accessible because they can be rendered through any sensory modality (for example, visual, auditory or tactile) to match the needs of the user. Providing text alternatives allows the information to be rendered in a variety of ways by a variety of user agents. For example, a person who cannot see a picture can have the text alternative read aloud using synthesized speech. A person who cannot hear an audio file can have the text alternative displayed so that he or she can read it. In the future, text alternatives will also allow information to be more easily translated into sign language or into a simpler form of the same language.
Additional information
Non-text content can take a number of forms, and this success criterion specifies how each is to be handled.
For non-text content that is not covered by one of the other situations listed below,
such as charts, diagrams, audio recordings, pictures, and animations, text alternatives can make the same information available in a form that can be rendered through any modality (for example, visual, auditory or tactile). Short and long text alternatives can be used as needed to convey the information in the non-text content. Note that
pre-recorded
audio-only and
pre-recorded
video-only files are covered here.
Live-audio-only and
Live-video-only files are covered below (see 3rd paragraph following this one).
For non-text content that is a control or accepts user input
, such as images used as submit buttons or complex animations, a name is provided to describe the purpose of the non-text content so that the person at least knows what the non-text content is and why it is there.
Non-text content that is multimedia
is made accessible through guideline 1.2. However it is important that users know what it is when they encounter it on a page so they can decide what action if any they want to take with it. A text alternative that describes the multimedia and/or gives its title is therefore provided.
Live Audio-only and live video-only files
- It is much more difficult to provide text alternatives that convey the same information as live audio-only and live video-only content. For these types of non-text content, text alternatives provide a descriptive label.
Sometimes a test or exercise must use a particular sense. Audio or visual information is provided that cannot be changed to text because the test or exercise must be conducted using that sense. For example, a hearing test would be invalid if a text alternative were provided. A visual skill development exercise would similarly make no sense in text form. And a spelling test with text alternatives would not be very effective. For these cases, text alternatives should be provided to describe the purpose of the non-text content; of course, the text alternatives would not provide the same information needed to pass the test.
Sometimes content is primarily intended to create a specific sensory experience that words cannot fully capture. Examples include a symphony performance, works of visual art etc. For such content, text alternatives at least identify the non-text content with a descriptive label and where possible, some descriptive text. If the reason for including the content in the page is known and can be described it is helpful to include that information.
[LC-787]
Sometimes there are non-text exercises that are used to prove you are human. To avoid spam robots and other software from gaining access to a site a device called a CAPTCHA is used. These usually involve visual or auditory tasks that are beyond the current capabilities of web robots. Providing a text alternative to them would however make them operable by Robots, thus defeating their purpose. In this case a text alternative would describe the purpose of the CAPTCHA, and alternate forms using different modalities would be provided to address the needs of people with different disabilities.
Sometimes there is non-text content that really is not meant to be seen or understood by the user. Transparent images used to move text over on a page; a one pixel transparent "web-bug" that tells the author when the page is viewed; and a swirl in the corner that conveys no information but just fills up a blank space to create an aesthetic effect are all examples of this. Putting alternative text on such items just distracts people using screen readers from the content on the page. Not marking the content in any way, though, leaves users guessing what the non-text content is and what information they may have missed (even though they have not missed anything in reality). This type of non-text content, therefore, is marked or implemented in a way that assistive technologies (AT) will ignore it and not present anything to the user.
Specific Benefits of Success Criterion 1.1.1:
This success criterion helps people who have difficulty perceiving visual content. Assistive technology can read text alternatives aloud, present them visually, or convert them to braille.
Text alternatives may help some people who have difficulty understanding the meaning of photographs, drawings, and other images (e.g. line drawings, graphic designs, paintings, three-dimensional representations), graphs, charts, animations, etc.
People who are deaf, are hard of hearing, or who are having trouble understanding audio information for any reason can read the text presentation. Research is ongoing regarding automatic translation of text into sign language.
[LC-790]
People who are deaf-blind can read the text in braille.
Additionally, text alternatives support the ability to search for non-text content and to repurpose content in a variety of ways.
Techniques for Addressing Success Criterion 1.1.1
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 F: If the non-text content should be ignored by assistive technology:
Implementing or marking the non-text content so that it will be ignored by assistive technology using one of the technology-specific techniques listed below
Providing short text alternatives in HTML
Providing long text alternatives in HTML
Common Failures Identified by the Working Group
The following are common mistakes that are considered failures of Success Criterion 1.1.1 by the WCAG Working Group.
Additional Techniques (Advisory) for 1.1.1
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.
General Techniques for Informative Non-Text Content (Advisory)
Identifying informative non-text content (future link)
Keeping short descriptions short (future link)
Describing images that include text (future link)
Providing a longer description of the non-text content where only a descriptive label is required using a technology-specific technique (for an accessibility-supported content technology) for long description listed above (future link)
General Techniques for Live Non-Text Content (Advisory)
Linking to textual information that provides comparable information (e.g. for a traffic Webcam, a municipality could provide a link to the text traffic report.) (future link)
[LC-788]
Providing a transcript of a live audio only presentation after the fact (future link)
HTML Techniques (Advisory)
H46: Using noembed with embed
(HTML)
[LC-786]
Writing for browsers that do not support frame (future link)
Providing alternative content for iframe (future link)
Providing text and non-text alternatives for object (future link)
Not using long descriptions for iframe (future link)
Providing redundant text links for client-side image maps (future link)
CSS Techniques (Advisory)
Using CSS margin and padding rules instead of spacer images (future link)
Using CSS background, :before or :after rules for decorative images instead of img elements (future link)
Displaying empty table cells (future link)
Examples of Success Criterion 1.1.1
A data chart
A bar chart compares how many widgets were sold in June, July, and August. The short label says, "Figure one - Sales in June, July and August." The longer description identifies the type of chart, provides a high-level summary of the data , trends and implications comparable to those available from the chart. Where possible and practical, the actual data is provided in a table.
[LC-789]
An audio recording of a speech (no video)
The link to an audio clip says, "Chairman's speech to the assembly." A link to a text transcript is provided immediately after the link to the audio clip.
An animation that illustrates how a car engine works
An animation shows how a car engine works. There is no audio and the animation is part of a tutorial that describes how an engine works. Since the text of the tutorial already provides a full explanation, the text alternative has a brief description of the image and refers to the tutorial text for more information.
[LC-1074]
A traffic Web camera
A Web site allows users to select from a variety of Web cameras positioned throughout a major city. After a camera is selected, the image updates every two minutes. A short text alternative identifies the Web camera as "traffic Web camera." The site also provides a table of travel times for each of the routes covered by the Web cameras. The table is also updated every two minutes.
A photograph of an historic event in a news story
A photograph of two world leaders shaking hands accompanies a news story about an international summit meeting. The text alternative says, "President X of Country X shakes hands with Prime Minister Y of country Y."
A photograph of a historic event in content discussing diplomatic relationships
The same image is used in a different context intended to explain nuances in diplomatic encounters. The image of the president shaking hands with the prime minister appears on a Web site discussing intricate diplomatic relationships. The first text alternative reads, "President X of country X shakes hands with Prime Minister Y of country Y on January 2, 2009." An additional text alternative describes the room where the leaders are standing as well as the expressions on the leaders' faces, and identifies the other people in the room. The additional description might be included on the same page as the photograph or in a separate file associated with the image through a link or other standard programmatic mechanism.
An audio recording
The Web page described in the previous example includes a link to an audio recording of the leaders' press conference. The page also links to a text transcript of the press conference. The transcript includes a verbatim record of everything the speakers say. It identifies who is speaking as well as noting other significant sounds that are part of the recording, such as applause, laughter, questions from the audience, and so on.
An e-learning application
An e-learning application uses sound effects to indicate whether or not the answers are correct. The chime sound indicates that the answer is correct and the beep sound indicates that the answer is incorrect. A text description is also included so that people who can't hear or understand the sound understand whether the answer is correct or incorrect.
[LC-1326]
A linked thumbnail image
A thumbnail image of the front page of a newspaper links to the home page of the "Smallville Times". The text alternative says "Smallville Times".
[LC-858]
Related Resources
Resources are for information purposes only, no endorsement implied.
Understanding Guideline 1.2:
Provide synchronized alternatives for multimedia
Intent of Guideline 1.2
The purpose of this guideline is to provide access to multimedia. Multimedia is defined in the glossary as:
multimedia: audio or video synchronized with another type of media and/or with time-based interactive components
Note that an audio file accompanied by interaction is covered here, as is a video-only file that involves interaction. These are covered because interaction must take place at a particular time. Having a text transcript that said, "for more information, click now," would not be very helpful since the reader would have no idea when the audio said, "now." As a result, synchronized captions would be needed.
Sometimes, there is so much dialogue that audio description cannot fit into existing pauses in the dialogue. The option at Level A to provide a full text alternative for multimedia including any interaction instead of audio description for multimedia would allow access to all of the information in the multimedia. This option also allows access to the visual information in non-visual form when audio description is not provided for some other reason.
For multimedia that includes interaction, interactive elements (for example links) could be embedded in the full text alternative for multimedia.
This guideline also includes (at Level AAA) sign language interpretation for multimedia as well as an approach called extended audio description. In extended audio description, the video is frozen periodically to allow more audio description to take place than is possible in the existing pauses in the dialogue. This is a case where higher-level success criteria build upon the requirements of lower-level SC with the intention of having cumulative, progressively stronger, requirements.
[LC-1223]
Advisory Techniques for Guideline 1.2 (not success criteria specific)
Specific techniques for meeting each success criterion for this guideline are listed in the understanding sections for each success criterion (listed below). If there are techniques, however, for addressing this guideline that do not fall under any of the success criteria, they are listed here. These techniques are not required or sufficient for meeting any success criteria, but can make certain types of Web content more accessible to more people.
Understanding Success Criterion 1.2.1 (Captions (Prerecorded))
- captions
text presented and synchronized with multimedia to provide not only the speech, but also non-speech information conveyed through sound, including meaningful sound effects and identification of speakers
[LC-846]
Note: In some countries, the term "subtitle" is used to refer to dialogue only and "captions" is used as the term for dialogue plus sounds and speaker identification. In other countries, subtitle (or its translation) is used to refer to both.
- multimedia
audio or video synchronized with another
format for presenting information and/or with time-based interactive components
[LC-1499]
- multimedia alternatives to text
multimedia that presents no more information than is already presented in text (directly or via text alternatives)
[LC-608]
Note: Multimedia alternatives to text are provided for those who benefit from alternate representations of text.
The intent of this success criterion is to enable people who are deaf or hard of hearing to watch multimedia presentations. Captions provide the part of the content available via the audio track. Captions not only include dialogue, but identify who is speaking and include non-speech information conveyed through sound, including meaningful sound effects.
It is acknowledged that at the present time there may be difficulty in creating captions for time-sensitive material and this may result in the author being faced with the choice of delaying the information until captions are available, or publishing time-sensitive content that is inaccessible to the deaf, at least for the interval until captions are available. Over time, the tools for captioning as well as building the captioning into the delivery process can shorten or eliminate such delays.
[LC-1332]
Captions are not needed when the multimedia is, itself, an alternate presentation of information that is also presented via text on the Web page. For example, if information on a page is accompanied by a multimedia presentation that presents no more information than is already presented in text, but is easier for people with cognitive, language, or learning disabilities to understand, then it would not need to be captioned since the information is already presented on the page in text or in text alternatives (e.g. for images).
[LC-608]
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.
The following are common mistakes that are considered failures of Success Criterion 1.2.1 by the WCAG Working Group.
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.
Providing a note saying "No sound is used in this clip" for video-only clips (future link)
Using SMIL 1.0 to provide captions for all languages for which there are audio tracks (future link)
Using SMIL 2.0 to provide captions for all languages for which there are audio tracks (future link)
A captioned tutorial
A video clip shows how to tie a knot. The captions read,
"(music)
Using rope to tie knots was an important skill
for the likes of sailors, soldiers and woodsmen.."
From Sample Transcript Formatting by Whit Anderson.
A complex legal document contains multimedia clips for different paragraphs that show a person speaking the contents of the paragraph. Each clip is associated with its corresponding paragraph. No captions are provided for the multimedia.
[LC-608]
An instruction manual containing a description of a part and its necessary orientation is accompanied by a multimedia clip showing the part in its correct orientation. No captions are provided for the multimedia clip.
[LC-608]
Resources are for information purposes only, no endorsement implied.
(none currently documented)
Understanding Success Criterion 1.2.2 (Audio Description or Full Text Alternative)
- audio description
narration added to the soundtrack to describe important visual details that cannot be understood from the main soundtrack alone
Note 1:
Audio description of video provides information about actions, characters, scene changes, on-screen text, and other visual content.
[LC-845]
Note 2:
In standard audio description, narration is added during existing pauses in dialogue. (See also extended audio description.)
Note 3:
Also called "video description" and "descriptive narration."
-
full text alternative for multimedia including any interaction
[LC-810]
document including correctly sequenced text descriptions of all visual settings, actions, speakers, and non-speech sounds, and transcript of all dialogue combined with a means of achieving any outcomes that are achieved using interaction (if any) during the multimedia
Note: A screenplay used to create the multimedia content would meet this definition only if it was corrected to accurately represent the final multimedia after editing.
- multimedia
audio or video synchronized with another
format for presenting information and/or with time-based interactive components
[LC-1499]
The intent of this success criterion is to provide people who are blind or visually impaired access to the visual information in a multimedia presentation. This success criterion describes two approaches, either of which can be used.
One approach is to provide audio description of the video content. The audio description augments the audio portion of the presentation with the information needed when the video portion is not available. During existing pauses in dialogue, audio description provides information about actions, characters, scene changes, and on-screen text that are important and are not described or spoken in the main sound track.
The second approach involves providing all of the information in the multimedia (both visual and auditory) in text form. A full text alternative for multimedia including any interaction provides a running description of all that is going on in the multimedia content. The full text alternative for multimedia including any interaction reads something like a screenplay or book. Unlike audio description, the description of the video portion is not constrained to just the pauses in the existing dialogue. Full descriptions are provided of all visual information, including visual context, actions and expressions of actors, and any other visual material. In addition, non-speech sounds (laughter, off-screen voices, etc.) are described, and transcripts of all dialogue are included. The sequence of description and dialogue transcripts are the same as the sequence in the multimedia itself. As a result, the full text alternative for multimedia can provide a much more complete representation of the multimedia content than audio description alone.
If there is any interaction as part of the multimedia presentation (e.g. "press now to answer the question") then the full text alternative for multimedia would provide hyperlinks or whatever is needed to provide the same functionality.
Note:
For 1.2.2, 1.2.3, and 1.2.7, if all of the information in the video track is already provided in the audio track, no audio description is necessary.
[LC-1224]
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.
The following are common mistakes that are considered failures of Success Criterion 1.2.2 by the WCAG Working Group.
(No failures currently documented)
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.
A movie with audio description.
Describer: A title, "Teaching Evolution Case Studies. Bonnie Chen." A teacher shows photographs of birds with long, thin beaks.
Bonnie Chen: "These photos were all taken at the Everglades."
Describer: The teacher hands each student two flat, thin wooden sticks.
Bonnie Chen: "Today you will pretend to be a species of wading bird that has a beak like this."
Describer: The teacher holds two of the sticks to her mouth making the shape of a beak.
Transcript of audio based on the first few minutes of "Teaching Evolution Case Studies, Bonnie Chen" (copyright WGBH and Clear Blue Sky Productions, Inc.)
A full text alternative for multimedia including any interaction for a training video
A company purchases a Training video for use by its employees and puts it on the companies intranet. The video involves explaining use of a new technology and has a person talking and showing things at the same time. Since there is no place to insert audio description of the visual demonstrations during gaps in dialogue, the company provides a full text alternative for multimedia that all employees, including those who cannot see the demonstrations, can use to better understand what is being presented.
Resources are for information purposes only, no endorsement implied.
Understanding Success Criterion 1.2.3 (Captions (Live))
1.2.3
Captions are provided for live
multimedia. (Level AA)
Note:
If multimedia is completely computer generated, it is not live and is subject to the requirements for pre-recorded multimedia in WCAG 2.0.
[LC-925]
- captions
text presented and synchronized with multimedia to provide not only the speech, but also non-speech information conveyed through sound, including meaningful sound effects and identification of speakers
[LC-846]
Note: In some countries, the term "subtitle" is used to refer to dialogue only and "captions" is used as the term for dialogue plus sounds and speaker identification. In other countries, subtitle (or its translation) is used to refer to both.
- multimedia
audio or video synchronized with another
format for presenting information and/or with time-based interactive components
[LC-1499]
The intent of this success criterion is to enable people who are deaf or hard of hearing to watch real-time presentations. Captions provide the part of the content available via the audio track. Captions not only include dialogue, but also identify who is speaking and notate sound effects and other significant audio.
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.
The following are common mistakes that are considered failures of Success Criterion 1.2.3 by the WCAG Working Group.
(No failures currently documented)
Resources are for information purposes only, no endorsement implied.
Understanding Success Criterion 1.2.4 (Audio Description)
- audio description
narration added to the soundtrack to describe important visual details that cannot be understood from the main soundtrack alone
Note 1:
Audio description of video provides information about actions, characters, scene changes, on-screen text, and other visual content.
[LC-845]
Note 2:
In standard audio description, narration is added during existing pauses in dialogue. (See also extended audio description.)
Note 3:
Also called "video description" and "descriptive narration."
- multimedia
audio or video synchronized with another
format for presenting information and/or with time-based interactive components
[LC-1499]
The intent of this success criterion is to provide people who are blind or visually impaired access to the visual information in a multimedia presentation. The audio description augments the audio portion of the presentation with the information needed when the video portion is not available. During existing pauses in dialogue, audio description provides information about actions, characters, scene changes, and on-screen text that are important and are not described or spoken in the main sound track.
Note:
For 1.2.2, 1.2.3, and 1.2.7, if all of the information in the video track is already provided in the audio track, no audio description is necessary.
[LC-1224]
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.
The following are common mistakes that are considered failures of Success Criterion 1.2.4 by the WCAG Working Group.
(No failures currently documented)
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.
A movie with audio description.
Describer: A title, "Teaching Evolution Case Studies. Bonnie Chen." A teacher shows photographs of birds with long, thin beaks.
Bonnie Chen: "These photos were all taken at the Everglades."
Describer: The teacher hands each student two flat, thin wooden sticks.
Bonnie Chen: "Today you will pretend to be a species of wading bird that has a beak like this."
Describer: The teacher holds two of the sticks to her mouth making the shape of a beak.
Transcript of audio based on the first few minutes of "Teaching Evolution Case Studies, Bonnie Chen" (copyright WGBH and Clear Blue Sky Productions, Inc.)
Resources are for information purposes only, no endorsement implied.
Understanding Success Criterion 1.2.5 (Sign Language)
- sign language interpretation
translation of one language, generally a spoken language, into a sign language
[LC-741]
Note:
True sign languages are independent languages that are unrelated to the spoken language(s) of the same country or region.
[LC-1504]
- multimedia
audio or video synchronized with another
format for presenting information and/or with time-based interactive components
[LC-1499]
The intent of this success criterion is to enable people who are deaf or hard of hearing and who are fluent in a sign language to understand the content of the audio track of multimedia presentations. Written text, such as that found in captions, is often a second language. Some individuals will require sign language interpretation to gain full access to the multimedia content.
[LC-591]
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.
The following are common mistakes that are considered failures of Success Criterion 1.2.5 by the WCAG Working Group.
(No failures currently documented)
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.
(none currently documented)
Example 1. A corporation is making an important announcement to all of its employees. The meeting will be held in the main headquarters and streamed to the Web. A sign language interpreter is provided at the meeting location. The live video includes a full view of the sign language interpreter as well as the person presenting.
Example 2. The same announcement described in example 1 is also Webcast to remote employees. Since there is only one display available for this, the sign language interpreter is shown in the corner of the display.
Example 3. A university is providing an on-line version of a particular lecture by creating a multimedia presentation of the professor delivering the lecture. The presentation includes video of the professor speaking and demonstrating a science experiment. A sign language interpretation of the lecture is created and presented on the Web with the multimedia version.
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Understanding Success Criterion 1.2.6 (Audio Description (Extended))
- extended audio description
audio description that is added to an audiovisual presentation by pausing the video so that there is time to add additional description
Note: This technique is only used when the sense of the