Definition for WCAG 2.0 success criterion 3.2.4
3.2.4 Consistent Identification: Components that have the same functionality within a set of Web pages are identified consistently.
The intent of this Success Criterion is to ensure consistent identification of functional components that appear repeatedly within a set of Web pages. A strategy that people who use screen readers use when operating a website is to rely heavily on their familiarity with functions that may appear on different Web pages. If identical functions have different labels on different Web pages, the site will be considerably more difficult to use. It may also be confusing and increase the cognitive load for people with cognitive limitations. Therefore, consistent labeling will help.
This consistency extends to the text alternatives. If icons or other non-text items have the same functionality, then their text alternatives should be consistent as well. See success criterion 1.1.1 Non-text Content (level A).
Note: further, this criterion extends to any other way in which the accessible name for a component is provided, such as the use of aria-label or aria-labelledby. See success criterion 4.1.2 Name, Role, Value (level A).
If there are two components on a web page that both have the same functionality as a component on another page in a set of web pages, then all 3 must be consistent. Hence the two on the same page will be consistent.
Note: this criterion applies to "pages within a set of Web pages". WCAG 2.0 defines this as a "collection of Web pages that share a common purpose and that are created by the same author, group or organization". This allows for some subjective interpretation on the part of a tester. In general all pages within a site can be considered part of a "set of Web pages"; specific sections of a site can also be interpreted as standalone "sets" of page, meaning that here the requirement would be for consistency within the set, rather than needing to be consistent with the rest of the overall site. For instance, all pages relating purely to the checkout process in an online store usually do not feature the full navigation found in the store-front part of the site (to avoid users accidentally navigating away/out of the checkout process).
Testing success criterion 3.2.4
Input into spreadsheet
- Fail
- Components that have the same functionality within a set of Web pages are not identified consistently.
- Pass
- All components that have the same functionality within a set of Web pages are identified consistently.
How to test
- Verify that components with a visible text label that have the same functionality within a set of Web pages are identified consistently (i.e. that the text used for the component on this page is the same as on other pages within the same set).
- For components with graphical / non-text labels, refer to success criterion 1.1.1 Non-text Content (level A) to ascertain the alternative text, then verify that this alternative text is consistent (i.e. that the alternative text used for the component on this page is the same as on other pages within the same set).
- For components that use additional ways to convey an accessible name (such as the use of
aria-labeloraria-labelledby), refer to success criterion 4.1.2 Name, Role, Value (level A) to ascertain the accessible name, then verify that this accessible name is consistent (i.e. that the accessible name used for the component on this page is the same as on other pages within the same set).