Job Safety

January 19, 2005

Fatigue and Performance

If a human testing technology is able to measure fatigue, is it also measuring overall performance? I would say yes it is, because fatigue affects many if not all aspects of performance. In other words, if someone is tired his/her performance is going to degrade across the board. And there is plenty of science to back this up. One classic study “The Human as a Limiting Element in Military Systems” tested a group of individuals over a grueling 72 hour no sleep trial.

The study used a variety of computer generated tests including pattern recognition, vigilance, logical reasoning, math performance and recall. What is remarkable is how consistent each of these tests was in measuring fatigue. Performance declined steadily with every type of test, although some tests look a little more stable than others.

The test battery was developed at Walter Reed Army Institute of Research by David R. Thorne, PhD. in 1982 and is still in use.