The intent of this success criterion is to ensure that functions that are triggered by moving a device (for example, shaking or tilting) or by gesturing towards the device so that sensors or the camera can pick up and interpret these gestures, can also be operated via user interface components, unless the motion is essential for the function and not using it would invalidate the activity.
Note: This criterion concerns input through sensors which respond directly to motions such as gesturing towards, tilting or shaking a device. It is not intended to cover the motion of users through space as registered by geolocation sensors or beacons, or events observed by the device other than intentional gestures by the user. It also does not cover indirect motion associated with operating a keyboard, pointer, or assistive technology.
Devices often have sensors that can act as inputs, such as accelerometer and gyroscope sensors on a phone or tablet device. These sensors can allow the user to control something by simply changing the orientation or moving the device in particular ways. In other situations, web content can interpret user gestures via the camera or other sensors to actuate functions, for example, to move forward or backward in a sequence of pages. Some users with disabilities are not able to operate these device sensors (either not at all or not precisely enough) because the device is affixed to a wheelchair or due to motor impairments. Functionality must therefore be implemented in a way that other means are available to activate the function that do not rely on sensor input.
In addition, some users may accidentally active sensors due to tremors or other motor impairments. The user must have the ability to turn off motion actuation to prevent such accidental triggering of functions. Applications may be able to meet this requirement by supporting operating system settings which allow the user to disable motion detection at the system level.
Some applications are specifically created to use device sensor data. Examples of content that are exempt from this requirement include a pedometer that relies on device motion to count steps.
None