Motion Actuation (2.5.4 – Level A)

Motion Actuation requires that functions operated by motion can also be operated through an interface and responding to motion can be disabled.

Introduction

Where gestures such as pointing or movements like a shaking or tilting control a function, some users will need to be able to control these through a more standard interface. Users with mobility impairments may not be able to make the correct movements (or make them precisely) enough to interact with these types of controls.

Similarly, some users may inadvertently use these controls and therefore need a way to switch them off.

How to Pass ‘Motion Actuation’

• Ensure users can enable and disable gesture and movement-based controls.
  
• Provide a standard interface (such as a button) in addition to motion and gesture controls.

Exceptions

• Where the motion operates a function through an accessible interface supported by the user’s assistive technology and:
  • The technology is supported widely (such as HTML); or
  • The technology is supported in a widely distributed plug-in; or
  • The content is within a closed environment or network where the user agent required is accessible; or
  • The user agents that support the technology are available at the same cost and as easily to users with and without disabilities. 
    
• Where the motion is essential for the function, for example a step counter that uses movement to calculate distance. 

‘Motion Actuation’ Tips

Ignore the exceptions and stick to providing alternate interface and the ability to disable motion controls.

See Also

Understanding Success Criterion 2.5.4 (W3C)