K. Woodcock, 2007. Proceedings of the Association of Canadian Ergonomists. [CD-ROM] 6 pgs.
There are many models of accident causation and human error that can explain and classify event data. However investigations in specific cases often fail to acquire all of the information needed to apply the models to an event. THEDA was developed as an interactive tool to aid the investigator to seek additional data about human errors involved in accidents and hazardous device failure situations. Using a hierarchically branching adaptive sequence of yes-no questions, THEDA promotes acquisition of data by prompting the investigation to probe into procedures, systems, conditions, and actions that created the situations in which the proximal individual responded ineffectively. A functioning mock-up has been created in spreadsheet form which compiles the user’s findings for reporting with general human factors comments. Although operational for trained users, its development is ongoing to enhance its general usability.