ABSTRACT
This chapter focuses on performance-based measures and their usefulness in indexing workload in terms of task-interference in dual-task performance. It summarizes findings from a research programme developed to examine systematically the role task-specific and task-unspecifc factors might play concerning the measurement and evaluation of workload and task-interference, respectively. The chapter demonstrates that methods for the assessment and evaluation of mental workload in dual-task performance should be based on a combined consideration of task-specific and task-unspecific factors. The data presented in the chapter have made clear that there are strong influences of task-unspecific factors which should be considered more carefully in future developments of mental workload assessment and analysis techniques. Given the assumption that in real workplaces performance errors have to be minimized during task performance, we are likely to argue that performance effectiveness is the most important variable with regard to application-oriented measures of workload and task-interference, respectively.
