Interruption Cost Evaluation by Cognitive Workload and Task Performance in Interruption Coordination Modes for Human-Computer Interaction Tasks

Abstract

Interruption is a widespread phenomenon in human-computer interaction in modern working environments. To minimize the adverse impact or to maximize possible benefits of interruptions, a reliable approach to evaluate interruption cost needs to be established. In this paper, we suggest a new approach to evaluate the interruption cost by cognitive workload and task performance measures. The cognitive workload is assessed by pupil diameter changes and National Aeronautics and Space Administration (NASA) task load index. Task performance includes task completion time and task accuracy in a series of controlled laboratory experiments. This integrated approach was applied to three interruption coordination modes (i.e., the immediate, the negotiated, and the scheduled modes), which were designed based on McFarlane's interruption coordination modes. Each mode consists of cognitive and skill tasks depending on the degree of mental demands providing four different task sets of interruptive task environments. Our results demonstrate that the negotiated mode shows a lower interruption cost than other modes, and primary task type and task similarity between primary and peripheral tasks are crucial in the evaluation of the cost. This study suggests a new approach evaluating interruption cost by cognitive workload and task performance measures. Applying this approach to various interruptive environments, disruptiveness of interruption was evaluated considering interruption coordination modes and task types, and the outcomes can support development of strategies to reduce the detrimental effects of unexpected and unnecessary interruptions.