The Residual Disruption Effect in Interrupted Task Performance

Christopher Monk

Advisor: Deborah A. Boehm-Davis, PhD, Department of Psychology

David J. King Hall, 2072
July 20, 2004, 08:00 PM to 07:00 PM

Abstract:

A study was undertaken to identify any disruptive effects beyond the initial time to resume the primary task after an interruption, and to determine the cause of any such residual disruption effect. The first experiment demonstrated that interruptions indeed had an effect on task performance beyond the initial time to resume the task. The presence of this effect showed for the first time that the cost associated with resuming an interrupted task lasted longer than the just the resumption time. Because residual disruption effect was newly discovered, there were no ready-made explanations for it. Therefore, the purpose of the remaining experiments was to explore possible explanations for this new effect. The second experiment tested the Activation Momentum explanation, which was based on mediated priming in spreading activation. This explanation maintained that the residual disruption effect was caused by higher activation levels for later goals in a hierarchical task, boosted over time as the person progresses through the task. The results showed that the effect was not due to an additive build-up of activation for future goals through mediated priming. Because the Activation Momentum explanation was unsupported, another explanation was considered and tested in the third experiment. The Cognitive-Perceptual Shift explanation argued that interruptions caused people to rely on their memory for the task for a short period before resuming performance that relied on the cues in the task environment. The results from Experiment 3 showed did not support this explanation. A third explanation was proposed and tested in Experiment 4. The Goal History explanation, which was based on Altmann and Trafton?s (2002) memory for goals framework, was centered on the recency and frequency of goal retrievals from memory, and how goal retrieval history can result in the residual disruption effect after an interruption. The results of the fourth experiment supported the Goal History explanation by drastically reducing the residual disruption effect when the repetition of goals, and therefore their activation history, was controlled. The empirical evidence from this set of four experiments demonstrated the existence of the residual disruption effect in hierarchical tasks, and supported the Goal History explanation. Indeed, the Goal History explanation was able to account not only for the residual disruption effect, it was also able to account for the effects found in the three previous experiments.