In order to evaluate intellectual productivity such as the efficiency of performing mental works, several studies have been conducted where the operational logs
of mental tasks were analyzed. However, it is also necessary to analyze several cognitive
states in mental workers so that the productivity can be evaluated accurately. In this
study, therefore, the Performance-Mental Effort Modeling has been proposed, where task
performance and cognitive load are employed in order to evaluate multi-cognitive-state in
mental workers. Besides, the inference method of multi-cognitive-state have been developed by using the operational logs of mental tasks as well as pupil diameter and heart rate
of the worker. As a result of the subject experiment, the authors found the feasibility of
this proposed method so as to evaluate several cognitive states in mental workers. This
method is expected to be the novel evaluation method of intellectual productivity.