Abstract: 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.

Abstract: A knowledge base processor is callable by an application program to access a knowledge base and to govern the execution or interpretation of the knowledge base to find the values of selected objects or expressions defined in the knowledge base. The application program is written in a conventional computer language which specifies control by the ordering of program steps. The application program provides a user interface for input/output and provides top level control for calling the knowledge base processor to find values for goal expressions. During its search for the values of goal expressions, the knowledge base processor calls the application program to determine values of expressions which are not concluded by the knowledge base, and to signal important events during the execution of the knowledge base. Preferably the knowledge base processor and the application program each include a library of subroutines which are linked-loaded to provide a complete knowledge system for a specific application or task.

Abstract: A tool is used for knowledge engineers for building and interpreting a knowledge base having separate portions encoding control knowledge, factual knowledge, and judgmental rules. The tool has an inference engine applying the judgmental rules according to a built-in control procedure defining discrete states or control steps during a consultation with a user. The control knowledge is encoded in an applicative and imperative language defining control actions to be executed during interruption of the built-in control procedure at specified control steps. Since the control knowledge is explicit and results in the modification of data only in a precisely defined fashion, the tool can be used to build knowledge systems that can always explain their conclusions and reasoning, and that are intelligible and modifiable.

Abstract: A tool for building a knowledge system and running a consultation on a computer is easily mastered by people with little computer experience yet also provides advanced capabilities for the experienced knowledge engineer. The knowledge system includes a knowledge base in an easily understood English-like language expressing facts, rules, and meta-facts for specifying how the rules are to be applied to solve a specific problem. The tool includes interactive knowledge base debugging, question generation, legal response checking, explanation, certainty factors, and the use of variables. The knowledge base language permits recursion and is extensible. Preferably, control during a consultation is goal directed in depth-first fashion as specified by rule order. The tool is easily embodied in assembly language, or in PROLOG to allow user-defined PROLOG functions.

Abstract: A knowledge system has a hierarchical knowledge base comprising a functional decomposition of a set of elements into subsets over a plurality of hierarchical levels, a plurality of predefined functions or conditions of the elements within the subsets of a plurality of the hierarchical levels, and a predefined set of operations to perform on a user-defined set of elements responsive to the functional knowledge base. Preferably, the knowledge base is defined declaratively by assigning parent sets to offspring subsets to define the hierarchy, by indicating the conditions of the subsets which satisfy the predefined functions and by writing task blocks in an imperative language defining the sequence of operations to perform on the user-defined set of elements. Preferably the operations include matching, configuring and expanding the user-defined set of elements into the defined subsets of individual elements and evaluating the predefined functions, and the operations are executed recursively.