Cursor movements to targets labelled "stop": a kinematic analysis.

Area of Science:

• Human-Computer Interaction
• Cognitive Psychology
• Usability Engineering

Background:

• Interface labels can create conflicting signals, such as 'STOP' implying both a command and a warning.
• Understanding how users resolve these label-command conflicts is crucial for safe and efficient interface design.

Purpose of the Study:

• To investigate the conflict between incongruent labels (e.g., 'STOP') and imperative commands (e.g., 'MOVE!').
• To analyze the impact of label-command incongruence on user performance metrics like response latency and accuracy.

Main Methods:

• 18 participants performed a computer-based task involving moving a cursor to targets with superimposed labels.
• Systematic variation of imperative commands (blank or 'MOVE!'), labels ('+GO+' or 'STOP'), and movement distance.
• Kinematic analyses were used to measure response latency, movement duration, and accuracy.

Main Results:

• Incongruent labels minimally affected response latencies but influenced cursor deceleration and placement variability.
• Responses to controls labeled 'STOP' were less accurate than those labeled '+GO+'.
• The impact of written labels on performance was not immediate, affecting cursor deceleration rather than initial latency.

Conclusions:

• Label-command confusions in interfaces can lead to errors.
• Enhancing control discriminability with clearer visual cues is recommended to mitigate confusion and improve usability.
• Interface design must consider potential conflicts between corrective actions and imperative commands.