The intent of this Success Criterion is to ensure more users can be made aware of important changes in content that are not given focus, in a way that doesn't unnecessarily interrupt their work.
The intended beneficiaries are blind and low vision users of assistive technologies with screen reader capabilities. As well, assistive technologies for users with cognitive disabilities may achieve an alternative means of indicating (or even delaying or supressing) status messages, as preferred by the user.
The scope of this Success Criterion is specific to changes in content that involve status messages. Information can frequently be added to pages which does not meet the definition of a status message. For example, the list of results obtained from a search are not considered a status update and thus are not covered by this Success Criterion. However, brief text messages displayed about the completion or status of the search, such as "18 results returned" or "no results returned" would be status updates. Examples of status messages are given in the section titled Status Message Examples below.
This Success Criterion specifically addresses scenarios where new content is added to the screen without changing the user's context. Changes of context, by their nature, interrupt the user; they are already surfaced by assistive technologies, and so have already met the objectives of this Success Criterion. Examples of scenarios that add new content by changing the context are given in the section titled Examples of Excepted Context Changes below.
Not all changes to content involve the addition of text to the screen. The following are all considerations relevant to this Success Criterion:
This Success Criterion was intentionally worded to apply primarily to visible changes of content. The reason for this is that where new text is displayed, it is intended to be visible to all users. By providing a programmatic means of ensuring the text is also surfaced through assistive technologies, the Success Criterion provides the same information to users who cannot or may not see it. However, the manner in which the information is displayed (for example its proximity to other pieces of information) may mean that the text change alone does not convey sufficient information to the user of the assistive technology.
In such cases, authors may wish to designate additional content for inclusion in the status message, including non-displayed text which can be provided to the assistive technologies, for added context. Important considerations regarding the appropriate use of such techniques are further discussed in the Sufficient Techniques.
If a status message persists on the page, modifications to this text are usually equivalent to a new status message. An example would be a shopping cart which updates text from reading "0 items" to "3 items". Typical methods of writing such changes in the page content result in the entire modified text string being considered a new change, and thus read by assistive technologies. However, where only the number in this string was coded as an updated chunk of content, the resulting experience for screen reader users would be to only hear "three", which may not be sufficient information to provide context for the user. In such situations, marking the entire "3 items" string as the status text would normally be a better solution.
In situations where status text is entirely removed, its absence may itself convey information about the status. The most obvious example of this is where a message is displayed that the system is "busy" or "waiting". For a sighted user, when this text disappears, it is normally an indication that the state is now available. However non-sighted users would be unaware of this change, unless the end of the waiting state results in a change of context for the user. The use of a non-visible status message, such as "system available", ensures equivalent status information is provided.
Changes in content are not restricted to text changes. Where an icon or sound indicates a status message, existing WCAG requirements governing text alternatives, under SC 1.1.1 Non-Text Content, in combination with this Success Criterion's requirement of an appropriate role, will allow the text alternative to be announced by the screen reader.
The following examples identify situations where no additional author action is necessary. All cases are excepted from this Success Criterion since they do not meet the definition of "status messages".
An author displays an error message in a dialog.
Since the dialog takes focus, it is defined as a change of context and does not meet the definition of a status message. As a result of taking focus, the new change of context is announced by the screen reader, and is not included in the scope of this Success Criterion.
Content is exposed or hidden when a user interacts with a user interface component, for example expanding components such as a menu, select, accordion or tree, or selecting a different tab item in a tablist.
None of the resulting changes to content meet the definition of status messages. Further, all components that meet the definition of a user interface component already have requirements specified under 4.1.2 Name, Role, Value, including the need to make notifications of changes to states available to user agents, including assistive technologies. As a result, changes in state, such as "expanded" or "collapsed," would be announced by the screen reader, and thus do not need to be addressed by this Success Criterion.
After a user completes an input that indicates they are unhappy, a series of new inputs are added to the page about customer satisfaction.
Since the new inputs do not "provide information to the user on the success or results of an action, on the waiting state of an application, on the progress of a process or on the existence of errors" they do not meet the definition of status message, and so are not required to meet this Success Criterion. [Note: Creating a status message about these controls being added, or notifying the user in advance that content changes may take place based on the user's response, are best practices, but are not requirements in this scenario.]
In addition to the use of non-displayed text for AT users, there are a number of considerations for content changes which are relevant to this Success Criterion, but which fall outside its scope. To prevent the possible perpetuation of poor design, the following best practices are discussed.
@@@ Cover all David's situations here? And also auto-updating? @@@
@@@ do we need situations, such as 'Situation A Where a status message is confirmation'? I think it would be an idea to see how many situations we can think of, and whether this provides clarify and guidance @@@