Human factors including pilot error are another potential danger, and currently the most common factor of aviation crashes. Much progress in applying human factors to improving aviation safety was made around the time of World War II by people such 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.[23] And 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 the captain