Interaction and motor behavior

Interaction

An affordance is a possible action supported by the relationship between an actor’s capabilities and an object or environment.

Interaction

Well-designed constraints limit invalid actions or make their boundaries clear while preserving valid choice and recovery.

Interaction

Direct manipulation lets people act on visible objects through incremental, rapid, and reversible operations with immediate feedback.

Interaction

Rapid, meaningful system feedback helps sustain an interactive rhythm; the often-cited 400 ms value is historical guidance, not a universal boundary.

Interaction

Every meaningful action should produce timely, perceivable feedback that accurately communicates the resulting system state.

Interaction

For aimed movement, acquisition time tends to increase with target distance and decrease with target size along the movement axis.

Interaction

In practiced choice-reaction tasks, response time tends to grow with the information uncertainty of the possible stimulus-response alternatives.

Interaction

A mapping feels natural when the arrangement or movement of controls corresponds clearly to the arrangement or behavior of their effects.

Interaction

Accept safe, unambiguous input variation where useful and produce predictable output, while rejecting ambiguity that threatens security or interoperability.

Interaction

Performance commonly improves quickly during early practice and more slowly later, but individual learning is not universally described by one power function.

Interaction

Information that must be mentally integrated often benefits from perceptual proximity, while information needing separate treatment may benefit from separation.

Interaction

Movement time through a constrained path tends to increase with path length and decrease with path width along the trajectory.

Interaction

Responses are generally faster and less error-prone when the relationship between a signal and its control matches learned or spatial expectations.