Are you engaged enough to perform? Proposing a trigger for adaptive automation

Many authors have suggested that level of automation in an adaptive system should be coupled to mental workload, which would ideally create a system in which mental workload experienced by the operator remains stable. Traditionally, mental workload has been defined as a ratio between resources required and resource available. This definition has led to the suggestion that mental workload might be an inadequate trigger for task allocation, since it does not take into account motivational factors; it is often implicitly assumed that people try to perform optimally. However, as this is not always the case, a measure parallel to the traditional workload measure, but which conceptually includes motivational aspects is suggested. Mental engagement, defined as the amount of resources actually mobilized for task perfromance, reflects effort an operator is willing to exert for task performance at a given moment. We further suggest that, within a participant, the resources one actually puts into a task and Task Complexity can explain Task Performance. Combining changes in Level of Engagement, Task Complexity and Task Performance could be used in an adaptive system in which Level of Engagement and Task Complexity determine type and moment of task allocations and Task Performance is used as a control variable