Perspective

I know what I need to do, but I can't reliably perform the action

The task is understandable, but the interaction demands more precision, movement, repetition or timing than the person can reliably provide.

Understanding the task does not mean the required physical interaction is usable.

Interface demands

• Motor precision
• Sustained movement
• Repetition
• Timing
• Input method
• Physical positioning

These describe what the interface requires from the person. They are not disability categories. The same demand can matter because of permanent, temporary or situational circumstances, device setup or input method.

What happens

A person understands exactly what should happen but cannot reliably hit a target, drag an item, hold an action, repeat an activation, perform several actions together, meet a timing requirement or accomplish the task with their available input method.

Why it matters

Failure can be misread as misunderstanding or user error when the actual barrier is the physical interaction the product has chosen to require.

Standards & guidance

Depending on the implementation, WCAG 2.2 criteria such as 2.1.1 Keyboard, 2.5.1 Pointer Gestures, 2.5.7 Dragging Movements and 2.5.8 Target Size (Minimum) may be relevant. A physical interaction can still deserve investigation when no specific criterion is established.

How to investigate it

Identify the exact action required. Separate understanding from performance. Check whether the same outcome can be achieved through another input method or a less precise, less sustained or less time-dependent action.

Evidence limit

Successfully performing the action once does not establish that it is reliable, comfortable or usable across people, devices, positions or input methods.