A cost effective question-asking strategy for Horn clause systems

In many applications of knowledge based systems, the initial data are insufficient to fulfill inference. In that case, knowledge based systems ask users questions in order to acquire more information. When and what to ask is determined by a question-asking strategy. This paper deals with question-asking strategies for a Horn system in which the response costs of the questions and the probablistic estimates of the answers are given. We introduce a question sequencing rule and enhance an efficient question-asking strategy. Our computational experiments show that the proposed question-asking strategy is very effective.Supported in part by the Office of Naval Research grant N00014-94-1-0355.Supported in part by the Office of Naval Research grant N00014-95-0639.