Expert System

The goal of this lecture is to clarify
Basic concepts behind expert systems
knowledge representation,
inference mechanisms,
problem solving.
techniques (knowledge engineering, rapid prototyping) used to construct expert systems,
tools used to construct expert systems.

According to Darlington:
“An expert system is a program that attempts to mimic human expertise by applying inference methods to a specific body of knowledge.”
According to Turban:
“An expert system is a system that employs human knowledge captured in a computer to solve problems that ordinarily require human expertise.”
It was quickly realized that the way to make progress was to focus on particular application domains, and expert systems started to appear. Early ones were
DENDRAL – molecular structure of chemical compounds.
MYCIN – diagnosis of bacterial infections.
The term expert system is used in a seminal paper by Alan Turing in 1937 related to a study in AI.

An Expert System (ES) is a computer program that reasons using knowledge to solve complex problems. (Feigenbaum, 1992)

Traditionally, computers solve complex problems by arithmetic calculations; and the knowledge to solve the problem is only known by the human programmer.