Switch choice in applied multi-task management.

摘要

Little to date is known concerning how operators make choices in environments where cognitive load is high and they are faced with multiple different tasks to choose from. This dissertation reviewed a large body of voluntary task switching literature concerning basic research into choice in task switching, as well as what literature was available for applied task switching. From this and a prior model, a revised model of task switching choice that takes into account specific task attributes of difficulty, priority, interest and salience, was developed. In the first experiment, it was shown that task difficulty and priority influenced switching behavior. While task attributes were hypothesized to influence switching, a second major influence is time on task. In the second experiment, it was shown that tasks indeed vary in their interruptability over time, and this was related in part to what task was competing for attention as well as the cognitive processing required for the ongoing task performance. In a third experiment, a new methodology was developed to experimentally assess the role of diminishing rate of returns for performing a task. This declining rate was expected (and did result in) a general increase of switching away from an ongoing task over time. In conclusion, while task attributes and time on task play a major role in task switching in the current studies, defining the time period for theorized effects appears to be the next major step toward understanding switching choice behavior. Additionally, though the experiments are novel and certainly make a major contribution, to the extent that behavior is only represented in them, the methodology may miss some amount of 'other' task behavior, such as visual sampling.