✎ Technique: Motion actuation

Ensure that functions that are triggered by moving a device (for example, shaking or tilting) or by gesturing towards the device (so that sensors like a camera can pick up and interpret the gesturing), can also be operated by more conventional user interface components, unless the motion is essential for the function or not using motions or gestures would invalidate the activity. 

Users who may be unable to perform particular motions (such as tilting, shaking, or gesturing) because the device may be mounted or users may be physically unable to perform the necessary movement, should still be able to operate all functionality by other means (e.g., touch or voice input).

Some users may accidentally activate sensors due to tremors or other motor impairments. The user must have the ability to turn off motion actuation to prevent accidental triggering of functions.

Examples

✗ Bad example #1

After text is input in a field, shaking a device shows a dialog offering users to undo the input; and, there is no mechanism for disabling motion actuation.

Screen capture of interface without cancel button

✓ Good example #1

An Undo button next to the text field offers the same functionality.

Screen capture of interface with cancel button

✗ Bad example #2

A user can tilt a device to advance to the next or a previous page.

Interface with a tilting feature

✓ Good example #2

Buttons or links are also provided to perform the same function.

Interface with a manual feature

✗ Bad example #3

A user can move or pan a device to change the view in an interactive photo.

Interface without manual controls

✓ Good example #3

A text option or button is also available to perform these same functions.

Interface with manual controls

✗ Bad example #4

A user can gesture towards the device to navigate content.

Gesture interface without manual controls

✓ Good example #4

Text option or button is also available to navigate.

Gesture interface with manual controls