Productivity and fatigue

In studying productivity, effects of environmental factors have focused only on performance. However, previous studies of the impact of the environment upon performance of mental tasks generally conclude that productivity research is somewhat confusing because the results are sometimes conflicting. In experiments, subjects may be highly motivated for a short time period, so it is very difficult to find differences in performance. In this paper, our research group used new methods to evaluate the factors affecting productivity. Not only task performance but also parameters of fatigue were investigated. Three subjective experiments using these evaluation methods to investigate the effect of productivity are summarized.