The explanation facility and the explanation effect

Abstract

The ability to explain reasoning processes used for problem solving distinguishes the expert system from other decision support systems. The explanation facility is intended to help the user critically analyze the expert system output. Studies investigating the explanation effect, however, report that the act of explaining an event's occurrence increases the perceived likelihood of the event. The consideration of expert system explanations, therefore, may lead to greater agreement with the system's output rather than the intended critical review of the output. This research examines the explanation effect resulting from the consideration of expert system explanations. The differential impact of considering expert system explanations is compared to the effect of generating written explanations. In addition, the differential impact of positive versus negative explanations is investigated. A hypothetical audit case was administered to 41 practicing auditors. An explanation effect was observed when the expert system explanation was negative. An explanation effect was not observed when the expert system explanation was positive. An explanation effect was not observed for either positive or negative self-generated explanations. Therefore, the most influential explanations were those which were expert system generated and negative or conservative in direction.