An Information-Based Approach to Learning for Rule-Based Expert Systems

Dr. Michael J. Pazzani
Department of Information and Computer Science
University of California, Irvine
pazzani@ics.uci.edu

4:00 pm Thur. Oct. 13 in 2310 Computer Sciences and Statistics Bldg.

A recent advance in concept formation, FOIL, The First Order Inductive Learner (Quinlan, 1990) learns constant-free Horn clauses, a useful subset of first-order predicate calculus. We describe the learning system, FOCL, the First Order Combined Learner that adds a compatible knowledge-intensive learning program to FOIL. We describe how FOCL use a variety of types of background knowledge to increase the class of problems that can be solved, to decrease the hypothesis space explored, and to increase the accuracy of learned rules. In particular, we concentrate on the problem when the background knowledge consists of an existing set of classification rules that are not entirely accurate on a database of classified examples. In this case, the learning process is focused on acquiring rules that improve the accuracy of the existing knowledge. We will report results on several small problems (chess end-games and loan processing) and on a larger problem involving the troubleshooting of a telephone network.