Accessibility Testing Standard

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 synchronized media presentations. Written text, such as that found in captions, is often a second language. Because sign language provides the ability to provide intonation, emotion and other audio information that is reflected in sign language interpretation, but not in captions, sign language interpretation provides richer and more equivalent access to synchronized media.

Provide people who are blind or visually impaired access to a synchronized media presentation beyond that which can be provided by standard audio description. This is done by periodically freezing the synchronized media presentation and playing additional audio description. The synchronized media presentation is then resumed. Because it disrupts viewing for those who do not need the additional description, techniques that allow you to turn the feature on and off are often provided.

Make audio visual material available to individuals whose vision is too poor to reliably read captions and whose hearing is too poor to reliably hear dialogue and audio description.
This approach involves providing all of the information in the synchronized media (both visual and auditory) in text form. 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.

Make information conveyed by live audio, such as web-based audio conferencing, live speeches and radio Webcasts, accessible through the use of a text alternative. A live text caption service will enable live audio to be accessible to people who are deaf or hard of hearing, or who cannot otherwise hear the audio. Such services use a trained human operator who listens in to what is being said and uses a special keyboard to enter the text with only a small delay. They are able to capture a live event with a high degree of fidelity, and also to insert notes on any non spoken audio which is essential to understanding the event.

Ensure that the purpose of many elements on a page can be programmatically determined, so that user agents can extract and present that purpose to users using different modalities.
Many users with limited vocabularies rely on familiar terms or symbols in order to use the web. However, what is familiar to one user may not be familiar to another. When authors indicate the purpose, users can take advantage of personalization and user preferences to load a set of symbols or vocabulary familiar to them.

Provide enough contrast between text and its background so that it can be read by people with moderately low vision (who do not use contrast-enhancing assistive technology). For people without color deficiencies, hue and saturation have minimal or no effect on legibility as assessed by reading performance. Color deficiencies can affect luminance contrast somewhat. Therefore, in the recommendation, the contrast is calculated in such a way that color is not a key factor so that people who have a color vision deficit will also have adequate contrast between the text and the background.
Text that is decorative and conveys no information is excluded.
Text that is larger and has wider character strokes is easier to read at lower contrast. The contrast requirement for larger text is therefore lower. This allows authors to use a wider range of color choices for large text, which is helpful for design of pages, particularly titles. 18 point text or 14 point bold text is judged to be large enough to require a lower contrast ratio.

Ensure that any non-speech sounds are low enough that a user who is hard of hearing can separate the speech from background sounds or other noise foreground speech content. The value of 20 dB was chosen based on Large area assistive listening systems.

Ensure that visually rendered text is presented in such a manner that it can be perceived without its layout interfering with its readability. People with some cognitive, language and learning disabilities and some low vision users cannot perceive the text and/or lose their reading place if the text is presented in a manner that is difficult for them to read.
People with some visual or cognitive disabilities need to be able to select the color of text and the color of the background. They sometimes choose combinations that seem unintuitive to someone without that disability.
For people with some reading or vision disabilities, long lines of text can become a significant barrier. They have trouble keeping their place and following the flow of text.
People with some cognitive disabilities find it difficult to track text where the lines are close together. Providing extra space between lines and paragraphs allows them to better track the next line and to recognize when they have reached the end of a paragraph.
People with certain cognitive disabilities have problems reading text that is both left and right justified. The uneven spacing between words in fully justified text can cause "rivers of white" space to run down the page making reading difficult and in some cases impossible. Text justification can also cause words to be spaced closely together, so that it is difficult for them to locate word boundaries.

Enable people who require a particular visual presentation of text to be able to adjust the text presentation as required. This includes people who require the text in a particular font size, foreground and background color, font family, line spacing or alignment.
This means implementing the text in a manner that allows its presentation to be changed or providing a mechanism by which users can select an alternate presentation. Using images of text is an example of an implementation that does not allow users to alter the presentation of the text within it.

Ensure that all content is operable from the keyboard. This is the same as Success Criterion 2.1.1, except that no exceptions are allowed. This does not mean that content where the underlying function requires input that depends on the path of the user's movement and not just the endpoints (excluded from the requirements of 2.1.1) must be made keyboard accessible. Rather, it means that content that uses path-dependent input cannot conform to this Success Criterion and therefore cannot meet Guideline 2.1 at Level AAA.

Minimize the occurrence of content that requires timed interaction. This enables people with blindness, low vision, cognitive limitations, or motor impairments to interact with content. This differs from the Level A Success Criterion in that the only exception is for real-time events.

Allow users to turn off updates from the author/server except in emergencies. Emergencies would include civil emergency alert messages or any other messages that warn of danger to health, safety, or property, including data loss, loss of connection, etcetera.
This allows access by people with cognitive limitations or attention disorders by enabling them to focus on the content. It also allows users who are blind or have low vision to keep their "viewing" focus on the content they are currently reading.

Allow all users to complete authenticated transactions that have inactivity time limits or other circumstances that would cause a user to be logged out while in the midst of completing the transaction.
For security reasons, many sites implement an authentication time limit after a certain period of inactivity. These time limits may cause problems for persons with disabilities because it may take longer for them to complete the activity. When users are logged out while still in the midst of a transaction - it is important that they be given the ability to re-authenticate and continue with the transaction without the loss of any data already entered.

Ensure that when a timeout is used, users know what duration of inactivity will cause the page to time out and result in lost data. The use of timed events can present significant barriers for users with cognitive disabilities, as these users may require more time to read content or to perform functions, such as completing an online form.
During the completion of an online process, such as to reserve a hotel room or purchase a plane ticket, a user with a cognitive impairment may become overwhelmed with lengthy instructions and data input required to complete the process. The user may not be able to complete the process in one sitting and may need to take a break. Users should be able to leave a process without losing their current place within the process, and without losing information that has already been entered. If users cannot take a break and check their work, many will often be unable to complete a task correctly.

Seizures cannot be completely eliminated since some people are so sensitive. However, by eliminating all 3-per-second flashing over any area of the screen, the chances of a person having a seizure are further reduced than when just meeting the measures ordinarily used today in standards internationally, as we do at Level A.
Whereas Success Criterion 2.3.1 allows flashing if it is dim enough or has a small enough area, Success Criterion 2.3.2 does not allow flashing greater than 3 per second, regardless of brightness or size. As a result, even a single flashing pixel would violate this criterion. The intent is to guard against flashing larger than a single pixel, but since an unknown amount of magnification or high contrast setting may be applied, the prohibition is against any flashing.

Allow users to prevent animation from being displayed on Web pages. Some users experience distraction or nausea from animated content. For example, if scrolling a page causes elements to move (other than the essential movement associated with scrolling) it can trigger vestibular disorders. Vestibular (inner ear) disorder reactions include dizziness, nausea and headaches. Another animation that is often non-essential is parallax scrolling. Parallax scrolling occurs when backgrounds move at a different rate to foregrounds. Animation that is essential to the functionality or information of a web page is allowed by this Success Criterion.

Provide a way for the user to orient herself within a set of Web pages, a Web site, or a Web application and find related information.

Help users understand the purpose of each link in the content, so they can decide whether they want to follow it. Best practice is that links with the same destination would have the same descriptions, but links with different purposes and destinations would have different descriptions. Because the purpose of a link can be identified from its link text, links can be understood when they are out of context, such as when the user agent provides a list of all the links on a page.
Having the link and the title agree, or be very similar, is good practice and provides continuity between the link 'clicked on' and the web page that the user lands on.
The Success Criterion includes an exception for links for which the purpose of the link cannot be determined from the information on the Web page. In this situation, the person with the disability is not at a disadvantage; there is no additional context available to understand the link purpose. However, whatever amount of context is available on the Web page that can be used to interpret the purpose of the link must be made available in the link text to satisfy the Success Criterion.

Provide headings for sections of a Web page, when the page is organized into sections. For instance, long documents are often divided into a variety of chapters, chapters have subtopics, etc. When such sections exist, they need to have headings that introduce them. This clearly indicates the organization of the content, facilitates navigation within the content, and provides mental "handles" that aid in comprehension of the content.

Ensure that the item receiving keyboard focus is always visible in the user's viewport. For sighted people who rely on a keyboard (or on a device that operates through the keyboard interface, such as a switch or voice input), knowing the current point of focus is critical. The component with focus signals the interaction point on the page. Where users cannot see the item with focus, they may not know how to proceed, or may even think the system has become unresponsive.
Typical types of content that can overlap focused items are sticky footers, sticky headers, and non-modal dialogs. As a user tabs through the page, these layers of content can hide the item receiving focus, along with its focus indicator.

Ensure a keyboard focus indicator is clearly visible and discernible. Focus Visible requires that a visible focus indicator exists while a component has keyboard focus; Focus Appearance defines a minimum level of visibility. Where Non-text Contrast requires a component to have adequate contrast against the background in each of its states, Focus Appearance requires sufficient contrast for the focus indicator itself.
For sighted people with mobility impairments who use a keyboard or a device that utilizes the keyboard interface (such as a switch or voice input), knowing the current point of focus is very important. Visible focus must also meet the needs of users with low vision, who may also rely on the keyboard.
A keyboard focus indicator can take different forms. This Success Criterion encourages the use of a solid outline around the focused user interface component, but allows other types of indicators that are at least as large.

Help users who may have trouble activating a small target because of hand tremors, limited dexterity or other reasons. If the target is too small, it may be difficult to aim at the target. Mice and similar pointing devices can be hard to use for these users, and a larger target will help them greatly in having positive outcomes on the web page.
Touch is particularly problematic as it is an input mechanism with coarse precision. Users lack the same level of fine control as on inputs such as a mouse or stylus. A finger is larger than a mouse pointer, and generally obstructs the user's view of the precise location on the screen that is being touched/activated.

Ensure that people can use and switch between different modes of input when interacting with web content. Users may employ a variety of input mechanisms when interacting with web content. These may be a combination of mechanisms such as a keyboard or keyboard-like interfaces and pointer devices like a mouse, stylus or touchscreen.
Even though a device may have a primary input mechanism, the user may choose to employ alternative input mechanisms when interacting with the device. For example, the primary mechanism for mobile phones and tablets is the touchscreen. The user of these devices may choose to use a paired mouse or external keyboard as an alternative to using the touchscreen.
Users should be able to switch input mechanisms at any point should the user determine that certain tasks and interactions are more easily accomplished by using an alternative input mechanism. Content must not limit the user's interaction to any particular input mechanism unless the restriction is essential, or is required to ensure the security of the content or to respect user settings.

Certain disabilities make it difficult to understand nonliteral word usage and specialized words or usage. Certain disabilities make it difficult to understand figurative language or specialized usage. Providing such mechanisms is vital for these audiences. Specialized information intended for non-specialist readers is encouraged to satisfy this Success Criterion, even when claiming only Single-A or Double-A conformance.

The intent of this Success Criterion is to ensure that users can access the expanded form of abbreviations (such as dr.).

Content should be written as clearly and simply as possible. This Success Criterion helps people with reading disabilities while also allowing authors to publish difficult or complex Web content. Text difficulty is described in terms of the level of education required to read the text. Education levels are defined according to the International Standard Classification of Education [UNESCO], which was created to allow international comparison among systems of education.
It may be possible to accommodate these users by making the text more readable. If the text cannot be made more readable, then supplemental content is needed. Supplemental content is required when text demands reading ability more advanced than the lower secondary education level. Reading disabilities such as dyslexia make it difficult to recognize written or printed words and associate them with the correct sounds.

Help people who are blind, people who have low vision, and people with reading disabilities to understand content in cases where meaning depends on pronunciation. Often words or characters have different meanings, each with its own pronunciation. The meaning of such words or characters can usually be determined from the context of the sentence.
When the sentence is read aloud and the screen reader reads the word using the wrong pronunciation, it can be even more difficult to understand than when read visually. When words are ambiguous or indeterminate unless the pronunciation is known, then providing some means of determining the pronunciation is needed. Such as the words desert (abandon) and desert (arid region). If pronunciation cannot be determined then some mechanism for determining the proper pronunciation would be required.

Encourage design of Web content that gives users full control of changes of context. This Success Criterion aims to eliminate potential confusion that may be caused by unexpected changes of context such as automatic launching of new windows, automatic submission of forms after selecting an item from a list, etcetera. Such unexpected changes of context may cause difficulties for people with motor impairments, people with low vision, people who are blind, and people with certain cognitive limitations.

Help users avoid make mistakes. Some users with disabilities may be more likely to make mistakes than users without disabilities. Using context-sensitive help, users find out how to perform an operation without losing track of what they are doing. Context-sensitive help only needs to be provided when the label is not sufficient to describe all functionality. The existence of context-sensitive help should be obvious to the user and they should be able to obtain it whenever they require it.

Help users with disabilities avoid consequences that may result from making a mistake when submitting form data.
Users with disabilities may be more likely to make mistakes and may have more difficulty detecting or recovering from mistakes. People with reading disabilities may transpose numbers and letters, and those with motor disabilities may hit keys by mistake. Providing the ability to reverse actions allows users to correct a mistake. Providing the ability to review and correct information gives the user an opportunity to detect a mistake before taking an action.

Ensure there is an accessible, easy-to-use, and secure method to log in, access content, and undertake tasks. That is, any required step of the authentication process cannot display a selection of images, videos, or audio clips, where users must choose which image they provided.