Human factors, including pilot error, are another potential set of factors, and currently the factor most commonly found in aviation accidents. Much progress in applying human factors analysis to improving aviation safety was made around the time of World War II by such pioneers as Paul Fitts and Alphonse Chapanis. However, there has been progress in safety throughout the history of aviation, such as the development of the pilot's checklist in 1937. CRM, or Crew Resource Management, is a technique that makes use of the experience and knowledge of the complete flight crew to avoid dependence on just one crew member.