Experiments with automatically created memory-based heuristics

Abstract

A memory-basedhe uristic is a function, h(s), storedi n the form of a lookup table: h(s) is computedb y mapping s to an index and then retrieving the corresponding entry in the table. In this paper we present a notation for describing state spaces, PSVN, anda method for automatically creating memory-basedheuri stics for a state space by abstracting its PSVN description. Two investigations of these automatically generated heuristics are presented. First, thousands of automatically generatedh euristics are used to experimentally investigate the conjecture by Korf [4] that m•t is a constant, where m is the size of a heuristic's lookup table and t is the number of nodes expanded when the heuristic is used to guide search. Second, a similar large-scale experiment is used to verify that the Korf and Reid's complexity analysis [5] can be used to rapidly andreliab ly choose the best among a given set of heuristics.