The Effects of Task Interruption on Human Performance: A Study of the Systematic Classification of Human Behavior and Interruption Frequency

Interruptions are prevalent phenomena in modern working environments; yet, few interruption studies have been conducted on different types of human tasks. A study using computer-based human behavior tasks was carried out to investigate the effects of interruptions with 4 different primary-interrupting task sets. The tasks used in this study were determined by cognitive and motor skill processes based on human behavior classification theory. The results showed that interruption effects were most negative in cognitive/cognitive task sets, and skill/cognitive task sets showed the least amount of effects in task completion time, F(3, 332) = 77.88, p < .001. In error rate performance, skill/skill task sets showed the highest rate, and error rates for cognitive primary task sets (cognitive/cognitive and cognitive/skill task sets) were not significantly different, F(1, 42) = 41.18, p < .001; F(1, 42) = 3.56, p = 0.0661. Interruption frequency also negatively affected task performance, F(1, 412) = 89.88, p < .001, but skill tasks' quantitative performance did not show significant effects at different interruption frequencies, F(1, 187) = 3.78, p = .0534. The results showed that interruptions increase more time to complete in cognitive tasks and produce more errors in skill tasks. Also, similar types of primary-interrupting tasks were more susceptible from interruptions. Thus, based on task composition of work process, we can estimate different effects from the interruptions and memory load, and task similarity in primary-interrupting task relationship were considered a main factor. (C) 2014 Wiley Periodicals, Inc.