The heuristic search under conditions of error

摘要

By placing various restrictions on the heuristic estimator it is possible to constrain the heuristic search process to fit specific needs. This paper introduces a new restriction upon the heuristic, called the “bandwidth” condition, that enables the ordered search to better cope with time and space difficulties. In particular, the effect of error within the heuristic is considered in detail.Beyond this, the bandwidth condition quite naturally allows for the extension of the heuristic search to MIN/MAX trees. The resulting game playing algorithm affords many desirable practical features not found in minimax based techniques, as well as maintaining the theoretical framework of ordered searches. The development of this algorithm provides some additional insight to the general problem of searching game trees by showing that certain, somewhat surprising changes in the cost estimates are required to properly search the tree. Furthermore, the use of an ordered search of MIN/MAX trees brings about a rather provocative departure from the conventional approach to computer game playing.