PPT Slide
...an intelligent computer program that uses knowledge
and inference procedures to solve problems that require
significant human expertise for their solution.
The knowledge of an expert systems consists of facts
and heuristics. Facts constitute the body of information
publicly available and agreed upon by experts in a field.
Heuristics are mostly private rules of good judgement
that characterize expert-level decision making in a field.
E. Feigenbaum, Stanford University