What does it mean for an interruption to be relevant? An investigation of relevance as a memory effect

Interruptions cause slower, more error prone performance. Research suggests these disruptive effects are mitigated when interruptions are relevant to the task at hand. However, previous work has usually defined relevance as the degree of similarity between the content of interruptions and tasks. Using a lab-based experiment, we investigated the extent to which memory effects should be considered when assessing the relevance of an interruption. Participants performed a routine data-entry task during which they were interrupted. We found that when participants were interrupted between subtasks, reinforcement and interference effects meant that relevance had a significant effect on interruption disruptiveness. However, this effect was not observed when participants were interrupted within subtasks. These results suggest that interruption relevance is contingent on the contents of working memory during an interruption and that interruption management systems could be improved by modelling potential interfering and reinforcing effects of incoming interruptions.