Learning Heuristic Functions Faster by Using Predicted Solution Costs.

Jabbari Arfaee, Zilles, and Holte presented the bootstrap learning system, a system that learns strong heuristic functions for state-space problems. They showed that IDA* with a bootstrap heuristic is able to quickly find near-optimal solutions in several problem domains. However, the process the bootstrap method uses to learn heuristic functions is time-consuming: it is on the order of days. In this paper we present a learning system that uses an approximation method instead of an exact one to generate the training set required to learn heuristics. We showed recently that solution costs can often be quickly and accurately predicted without having to actually find a solution. In this paper we apply this idea to speedup the process of learning heuristics. In contrast with other learning approaches that use search algorithms to solve problem instances to generate the training set, our system uses a solution cost predictor. We reduce the time required to learn strong heuristics from days to minutes on the domains tested.