41. A method of comparing the performance of a subject system to the performance of a knowledge system, said knowledge system comprising a computer having a memory, said memory storing a knowledge base encoding knowledge about a particular subject domain, said computer having a knowledge base interpreter for interpreting said knowledge base to solve specified problems pertaining to said subject domain and indicating the methods of solution to a subject system, said method comprising the steps of: (a) operating said computer to scan the knowledge base and determine a set of conditions of interest suitable for interrupting the interpretation of said knowledge base while solving specified problems pertaining to said subject domain, (b) operating said computer to transmit to a human user an indication of said set of conditions of interest, (c) operating said computer to receive from said human user an indication of a subset of said set of conditions, (d) operating said knowledge base interpreter to solve a specified problem pertaining to said subject domain, and while operating said knowledge base interpreter, operating said computer to test for the occurrence of said conditions included in said subset of conditions, and upon the occurrence of a condition included in said subset of conditions, to interrupt the operation of said knowledge base interpreter and to (e) probe the subject system to obtain a response about the status of the solution of said problem by said knowledge base interpreter, and (f) compare said response to the actual status of the solution of said problem by said knowledge base interpreter.
41. A method of comparing the performance of a subject system to the performance of a knowledge system, said knowledge system comprising a computer having a memory, said memory storing a knowledge base encoding knowledge about a particular subject domain, said computer having a knowledge base interpreter for interpreting said knowledge base to solve specified problems pertaining to said subject domain and indicating the methods of solution to a subject system, said method comprising the steps of: (a) operating said computer to scan the knowledge base and determine a set of conditions of interest suitable for interrupting the interpretation of said knowledge base while solving specified problems pertaining to said subject domain, (b) operating said computer to transmit to a human user an indication of said set of conditions of interest, (c) operating said computer to receive from said human user an indication of a subset of said set of conditions, (d) operating said knowledge base interpreter to solve a specified problem pertaining to said subject domain, and while operating said knowledge base interpreter, operating said computer to test for the occurrence of said conditions included in said subset of conditions, and upon the occurrence of a condition included in said subset of conditions, to interrupt the operation of said knowledge base interpreter and to (e) probe the subject system to obtain a response about the status of the solution of said problem by said knowledge base interpreter, and (f) compare said response to the actual status of the solution of said problem by said knowledge base interpreter. 42. The method as claimed in claim 41, wherein said knowledge base includes rules concluding values for expressions, and said step (a) of operating said computer to scan the knowledge base includes determining a list of expressions concluded by the rules, said step (b) includes transmitting to the human user said list of expressions concluded by the rules, and step (c) includes receiving from the user a subset of the expressions included in said list, said step (d) includes interrupting the operation of the knowledge base interpreter each time when the knowledge base interpreter finds the value for an expression in said subset, said step (e) probes the subject system for information pertaining to the expression which had its value found and caused the interruption of said knowledge base interpreter.