Reconstructive expert system explanation

Existing explanation facilities are typically far more appropriate for knowledge engineers engaged in system maintenance than for end-users of the system. This is because the explanation is little more than a trace of the detailed problem-solving steps. An alternative approach recognizes that an effective explanation often needs to substantially reorganize the actual line of reasoning and bring to bear additional information to support the result. Explanation itself becomes a complex problem-solving process that depends not only on the actual line of reasoning, but also on additional knowledge of the domain. This paper presents a new computational model of explanation and argues that it results in significant improvements over traditional approaches.