At least 5 different perceptions of the accident phenomenon, 44 different reasons for investigating accidents, 7 investigative processes, 6 general methodologies, and 3 differing types of output requirements affect accident investigations. These differences reflect the lack of a unifying conceptual framework for accident investigation and safety; corrupt data search, selection, organization and
... [Show full abstract] reporting decisions during investigations; and result in spurious accident data. A tentative unifying perception of accident phenomena, with supporting assumptions, principles and rules of procedure for their investigation was synthesized from the findings. Four games simulating the resultant accident investigation process have been developed. The process has been applied to improve hazardous materials emergency response decision making, and evaluation of safety countermeasures.