Naive judgements of stimulus-response compatibility

Area of Science:

• Human-Computer Interaction
• Cognitive Psychology
• Experimental Psychology

Background:

• Previous research by Payne (1995) and Vu & Proctor (2003) indicated naive users struggle to accurately judge interface usability.
• Naive judgments were limited to identifying the best design, lacking precision in other usability aspects.
• The current study extends this by investigating response time and subjective judgments under varying stimulus-response compatibility.

Purpose of the Study:

• To investigate the factors influencing response time in human-computer interaction.
• To assess the accuracy of subjective response time (SRT) judgments compared to actual reaction times.
• To determine the impact of stimulus-response arrangement geometry on user expectancy and interface design evaluation.

Main Methods:

• Experimentation with one, two, four, and eight light/key arrangements with varying compatibility levels.
• Measurement of actual response times and subjective response times (SRT) under different conditions.
• Comparison of SRT accuracy when subjects evaluated full sets of stimuli versus individual sets.

Main Results:

• Response time is significantly determined by response uncertainty (number of combinations) and stimulus-response location correlation.
• These two factors accounted for up to 93% of the variance in experimental reaction times.
• Subjective response time (SRT) accurately reflected actual reaction times, especially when subjects reviewed all possible scenarios beforehand.

Conclusions:

• High user expectancy, achieved through congruent stimulus and response locations, is essential for reducing reaction times and errors in interface design.
• The geometrical layout of stimuli and response arrangements can be used to evaluate interface design effectiveness.
• Subjective response time assessments are reliable when users have a comprehensive understanding of the task context.