Influence of work motivation and task difficulty on human reliability

The human reliability analysis (HRA) has long been focusing on determining causes of human error. Most current HRA studies concentrate on the influence of external context factors, such as working conditions, task time, etc., on human performance while ignoring internal psychological factors, for example, personality characteristics, feelings, motivations and so on. To explore both internal and external factors' impact on human reliability, we designed an experiment measuring the effects of work motivation, task difficulty on human error probability (HEP). 120 subjects participated in the experiment. The task difficulty levels in the experiment are much depends on the subjects' experience and training conditions. The results demonstrate that the general relationship between work motivation and HEP can be described by a U curve and the optimal work motivation is shifted with different task difficulty level, which also fit with Yerkes-Dodson Law.