Information Retrieval Techniques in Rule-based Expert Systems

In rule-based expert systems knowledge is represented in an IF-THEN form: IF THEN . A limited subset of natural language — supplemented by specified relations and operators — is used to formulate the rules. Rule syntax is simple. This makes it easy to acquire knowledge through an expert and permits plausibility checks on the knowledge base without the expert having knowledge of the implementation language or details of the system. A number of steps are used to select suitable rules during the rule-matching process. It is noteworthy that rules are well structured documents for an information retrieval system, particularly since the number of rules in a rule-based system remains manageable. In this paper it will be shown that this permits automatic processing of the rule set by methods of information retrieval (i.e. automatic indexing and automatic classification of rules, automatic thesaurus construction to the knowledge base) . A knowledge base which is processed and structured in this fashion allows the use of a complex application-specific search strategy and hence an efficient and effective realization of reasoning mechanisms.