Explanation is crucial in persuading others of the correctness of our beliefs to gain acceptance of our conclusion. Early research into expert systems focused on methods for reasoning. However it became apparent that the ultimate success lay in the ability to gain user acceptance by explaining the reasoning behind the conclusion. This study examines explanation from a social and an implementation standpoint. The social aspects of explanation provide insight into the role of naturally occurring explanations and listener expectations. Examination of research expert systems with explanation facilities and modifications of a simple Prolog expert system shell demonstrate the techniques required to simulate naturally occurring text. The modified shell produces improved explanations over the original shell, clearly indicating the desirability of natural appearance for gaining user acceptance
