Resumption Errors Following an Interruption in a Hierarchically Structured Task With Novices and Experts

Melanie LeGoullon

Advisor: .

David J. King Hall, 2073
June 08, 2008, 08:00 PM to 07:00 PM

Abstract:

It has long been known that interruptions can be disruptive, but details about where people resume an interrupted task and the errors they make have been largely overlooked. In two experiments, participants were asked to perform a hierarchical data entry task in which they were interrupted several times. Experiment 1 found that participants were significantly more likely to commit an error on the first step immediately following an interruption than on any other step. This rise in error rate mirrored a rise in response latency on the resumption point known as the resumption lag. However, the gradual speed-up effect over the course of several steps following an interruption was not mimicked in the error data. Experiment 1 also showed a bias toward repeating steps rather than skipping steps when an error is made on the resumption point. Experiment 2 showed that the deleterious effects on errors were mitigated with expertise, but response times were not. Taken together, these results suggest that the disruptive effect of interruptions is not distributed across the span of a task but rather largely is localized to the first few moments immediately following an interruption. They further suggest a bias in the cognitive system toward redundant actions when errors occur. Finally, these results suggest that training and experience can mitigate interruption-induced errors, but not necessarily the robust resumption lag effect.