Demand Transitions and Tracking Performance Efficiency: Structural and Strategic Models

A compensatory tracking task with hard and easy levels of difficulty was used to test resource depletion and effort regulation models of dual-to-single task transition effects. Both models were supported by the data. Consistent with a resource depletion view, participants who shared the difficult tracking task with a vigilance task during an induction phase, and then performed the tracking task alone during a transition phase, had greater levels of tracking error in both phases than those who were confronted only with the tracking task. By contrast, in accord with expectations derived from the effort regulation view, tracking error on the easy task was smaller during both phases of the study for participants who originally shared tracking with vigilance than for those confronted only with the tracking task. Evidently, task difficulty is a key factor in determining the domains in which these models apply.