Users of accessibility services, such as screen readers, rely on text labels to interact with user interfaces.
Screen readers announce the text label along with information about the type or state of the element. As a result, it isn't necessary for app developers to include information about type or state within the labels. For example:
- When TalkBack announces a clickable
Buttonelement, it appends the word "button" to the text label provided by the developer. If the developer includes "button" in the text label (such as "Save button"), TalkBack might speak the word "button" twice ("Save button button"). - If an interface has a
CheckBoxelement, the screen reader determines whether the element is checked and announces "checked" or "not checked" along with the text label provided by the developer. If the developer includes "checked" or "not checked" in the text label, the user might hear this information twice.
Assistive technologies often define their own set of gestures or interaction behaviors that are tailored to their users' needs. App-provided accessibility labels depend on the assistive technology used and should not provide specific interaction instructions, which might be incorrect. For example:
- TalkBack includes its own interaction instructions, “Double tap to select,” to describe clickable UI elements. If these instructions are included within the app-provided accessibility labels, TalkBack might speak these interaction instructions twice. If provided by the app, those same instructions wouldn’t be appropriate for a Switch Access user.
Implementation
Design
See the Material Design accessibility guidelines for more guidance on writing effective labels for accessibility purposes.
Testing
To manually identify user interface elements that are labeled with their type or state:
- Turn on TalkBack.
- Open the app.
- Move accessibility focus to the item to be evaluated.
- Listen to TalkBack’s spoken description of the focused item. Check if the item's type or state is included in this description more than once.
Android's automated testing tools can detect some instances of user interface elements labeled with their type, state, or interaction instructions. Consider using Accessibility Scanner for Android for manual testing of your app on-device. For automated tests, turn on accessibility checking in Espresso and Robolectric.