Why are rule-based systems important?

• As engineering, they give one way of implementing expert systems. These were the first big commercial application to result from AI. Closely related to other developments, including logic programming (the use of Prolog and its ilk as programming languages) and CYC. Made AI visible to outsiders; inspired 5th Generation project and reactions thereto; much hype.

• As psychology, used under the name of production systems as cognitive models. Long history, largely inspired by Allen Newell, culminating in his view of the SOAR production system as a unified theory of cognition.