The Structural Constraints and Strategic Control of Resource Allocation

Time-sharing performance was evaluated as a function of the structural configurations of the time-shared tasks and strategic resource-allocation training. A secondary task technique was employed with five task pairs that varied in their structural similarity. The primary task difficulty was time-varying within a trial. Consistent with a common finding in the literature, the global performance measures showed that the degree of task interference increased as the degree of shared resources between the time-shared tasks increased. The moment-by-moment performance, however, revealed that small task interference did not necessarily indicate that the primary task performance was consistently protected against the time-varying difficulty changes. Subjects' failure in protecting the primary task performance was attributed to two possible causes: a skill limitation in the control of resource allocation and a structural limitation inherent in the dual task configuration. This distinction was reinforced by the finding that the strategy training was successful in improving resource allocation for the structurally identical task pair only. Our data demonstrated the role of multiple resource concepts in predicting time-sharing performance in a dynamic environment.