%A William J. Clancey %J Artificial Intelligence %T Notes on "Epistemology of a Rule-based Expert System" %X In the 1970s, we conceived of a rule explanation as supplying the causal and social context that justifies a rule, an objective documentation for why a rule is correct. Today we would call such descriptions post-hoc design rationales, not proving the rules? correctness, but providing a means for later interpreting why the rule was written and facilitating later improvements. %N 1-2 %K expert systems, rule-based, MYCIN, NEOMYCIN, explanation systems, design rationale %P 191-204 %V 59 %D 1993 %L cogprints292