[comp.ai.digest] Seminar - Learning Search Control Knowledge

dlm@research.att.COM (01/30/88)

Learning Effective Search Control Knowledge: An Explanation-Based Approach

Steven Minton
Carnegie-Mellon University

Monday, February 1, 1988
10:30 AM

AT&T Bell Laboratories - Murray Hill  3C-436


In order to solve problems more effectively with accumulating
experience, a problem solver must be able to learn and exploit search
control knowledge. In this talk, I will discuss the application of
explanation-based learning (EBL) techniques for acquiring
domain-specific control knowledge. Although previous research has
demonstrated that EBL is a viable approach for acquiring control
knowledge, in practice EBL may not always generate useful control
knowledge. For control knowledge to be effective, the cumulative
benefits of applying the knowledge must outweigh the cumulative costs of
testing whether the knowledge is applicable. Generating effective
control knowledge may be difficult, as evidenced by the complexities
often encountered by human knowledge engineers. In general, control
knowledge cannot be indiscriminately added to a system; its costs and
benefits must be carefully taken into account.

To produce effective control knowledge, an explanation-based learner
must generate "good" explanations -- explanations that can be profitably
employed to control problem solving.  In this talk, I will discuss the
utility of EBL and describe the PRODIGY system, a problem solver that
learns by searching for good explanations. I will also briefly describe
a formal model of EBL and a proof that PRODIGY's generalization
algorithm is correct.

Sponsor:  Ron Brachman