Processing Resources in Attention, Dual Task Performance, and Workload Assessment.

This report develops the concept of multiple resource theory in dual task performance and describes its relation to the measurement of operator work-load. Structural and capacity theories of attention and time-sharing are contrasted, and the latter are then elaborated to describe the quantitative relation between resources and performance, and the representation of dual task data by the performance operating characteristic within a resource framework. Some deficiencies with a single resource (undifferentiated capacity) model of time-sharing are pointed out, and the multiple resources model is introduced. Data are presented supporting a specific model that defines resources by stages of processing, codes of processing, and modalities of encoding. This report discuss the relation between multiple resources and operator performance strategies, and different measures of operator workload. The different implications of multiple resource theory on primary task, secondary task, and physiological and subjective measures of workload, and the relations between these are considered.