Abstract
In this study, task characteristics of mental work are classified in order to establish an effective way to measure mental workload. Rasmussen's model is used to classify mental work into skill-based, rule-based, and knowledge-based tasks. Experiments are designed by considering these three levels of task characteristics, and the performance for each task is measured. The results show that for skill-based or rule-based tasks, changes of performance during one-hour experiments are small, whereas for knowledge-based tasks, changes are big. The graphs of accumulated performances illustrate the characteristics of each task. The results of our investigation on subjective symptoms, especially concerning “sleepiness and dullness”, differed for each of the tasks. These results indicate that the classification of mental work by using Rasmussen's model is useful for identifying the characteristics of the mental tasks, which is needed for selecting an effective method of measuring mental strain.
