A framework of expert system with strategic knowledge

The purpose of this study is to construct a system (an Extended Production System, for short, EPS) which selects a desirable strategy dynamically depending on its current state in the process of problem solving. In EPS, a special purpose production interpreter, which directs the system to change its strategies in cooperation with strategic rules, is provided on top of a Conventional Production System (for short, CPS). Furthermore, a set of tactic rules which is appropriate for the strategy is selected from a rulebase and used in order that CPS can restrict search space under the current strategy. This has made EPS capable of following up various problem solving requirements flexibly. A reduction of the number of comparisons between the tactic rules and Short Term Memory (STM) has been attained by declaration of a rule subset appropriate for the strategy in each strategic rule. These advantages have been examined through experiments in image data retrieval by examples.