KNOWLEDGE BASED TUTOR

A knowledge system has a consultation system and also encodes domain-dependent tutoring knowledge as a set of conditions for interrupting the operation of the consultation system in order to evaluate a subject system. During the evaluation, the subject system is probed for its understanding of the status of the consultation system, and its understanding is compared to the actual status to obtain a measure of the subject system's knowledge and performance relative to that of the consultation system. The direction of the probing and the source of information for instruction or diagnosis is based upon the condition causing the interruption of the consultation system. Preferably an authoring system scans the domain-dependent knowledge base of the consultation system and determines a set of possible interrupt conditions. From this set a user exercises judgment in selecting a subset of conditions that are appropriate for the subject domain and the needs of the student. The selected conditions and a selected test case dialog are stored in a case file, and a number of different case files may be stored in a case library. The authoring system preferably creates a file or index of tutorial knowledge which correlates the relevant domain knowledge with the interrupt conditions. The tutorial knowledge includes, for example, expressions for causing interrupts after their values are found, rules concluding the expressions, the values concluded by the rules, and the factors in the rules.