Alkov, Borowsky, and Gaynor started a 22-item questionnaire for U.S. Naval aviators in 1982 to test the hypothesis that inadequate stress coping strategies contributed to flight mishaps. The questionnaire consists of items related to lifestyle changes and personality characteristics. After completing the questionnaire, the test group is divided into two groups: "at-fault" with mishap, and "not-at-fault" in a mishap. Then, questionnaires from these two groups were analyzed to examine differences. A study of British commercial airline pilots, conducted by Sloan and Cooper (1986), surveyed 1,000 pilot members from the British Airline Pilots' Association (BALPA). They used a modified version of Alkov, Borowsky, and Gaynor's questionnaire to collect data on pilots' perceptions of the relationship between stress and performance. Being a subjective measure, this study's data was based on pilots' perceptions, and thus rely on how accurately they recall past experiences their relationships to stress. Despite relying on subjective perceptions and memories, the study showed that pilot reports are noteworthy.