Task interruption is a pervasive applied problem despite a dearth of experimental work and the absence of a developed theoretical framework. Using a novel experimental approach (interrupting problem solving in the Tower of Hanoi task), and theoretical guidance from ACT-R-based models of goal suspension and resumption (Altmann & Trafton, 2002 Anderson & Douglass, 2001), nine experiments were conducted to assess how goal-directed behaviour is affected by interruption. A cost of interruption was exhibited mainly by extended times to resume an interrupted goal compared to an uninterrupted goal. The first empirical series established performance impairments in the form of long resumption latencies for promptly suspended goals and decrements in move accuracy, especially when interruption fell before or during a complex goal-sequence, with performance impaired further by secondary tasks that were similar to primary tasks. The second empirical series revealed that participants opportunistically encode promptly suspended goals for retrieval, a process supported by the associative activation provided by a salient colour priming cue and impaired when such a cue had changed colour and/or location. With a brief time lag before secondary task initiation, participants were able to encode a suspended goal more efficiently, reflected in faster resumption latencies even when secondary tasks were similar and when interruption fell within a complex goal sequence. The findings suggest that suspended goals do not reside in a heightened level of activation such that retrieval is definite (e.g., Goschke & Kuhl, 1993) neither is retrieval always abandoned at longer retention intervals (as suggested by Anderson & Lebiere, 2001). Instead, goals decay as a power function of the time since they were last processed and suffer retroactive interference from other goals, but can be reactivated if appropriately rehearsed and associated with salient retrieval cues (in support of Altmann & Trafton, 2002). In contrast to Altmann and Trafton, participants exhibit retrieval-like behaviour even when interruption is un-signalled, with efficiency augmented by experience of problem solving in the task domain and experience of being interrupted. The current experiments provide a novel insight into interruption management behaviours, particularly that humans are able and willing to adapt strategies to support faster and more efficient transitions back into the primary task.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:583623 |
| Date | January 2005 |
| Creators | Morgan, Phillip L. |
| Publisher | Cardiff University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://orca.cf.ac.uk/55588/ |
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