Previous studies of multitasking have highlighted the importance of cognitive load in interruptibility by showing that forced interruptions are least disruptive when cognitive load is low, and also that users prefer to address interruptions at low-load points when given a choice. We present an empirical study that uses a ringing-phone scenario to examine how users manage deferrable interruptions in the presence of varying time constraints. We found that while cognitive load did influence

more »

... sking as expected, the time constraints placed on the user also had a significant impact. In particular, we observed three distinct strategies for addressing interruption: the expected strategy of switching at lowload points, but also two other strategies of continuing on after a low-load point or giving up at a high-load point. The presence of the latter two strategies strongly suggests that users can adapt their multitasking behavior with respect to the time constraints of the interrupting task.