Model-Based Predictions of Interrupted Checklists

The improper completion of a cockpit checklist has contributed to a number of aviation accidents. In many of these cases, it can be shown that interruptions were a contributing factor in the failure to complete the checklist properly. Unfortunately, most studies of interruptions have provided only post-hoc explanations for these failures. Further, research has focused on whether or not tasks are resumed rather than on predictions of where people will resume a task after an interruption. This paper describes several generic models that were used to explore cognitive strategies for handling interruptions. One of these models was then modified to fit the specific real-world task of completing an aircraft checklist. This model produced detailed a priori predictions about where the interrupted checklist will be resumed. The implications of these predictions for task design and for the use of cognitive modeling as an approach to understanding interruptions are discussed.