Planning with Primary E ects: Experiments and Analysis

The use of primary eeects in planning is an eeective approach to reducing search. The underlying idea of this approach is to select certain \important" eeects among the eeects of each operator and to use an operator only for achieving its important eeects. In the past, there has been little analysis of planning with primary eeects and few experimental results. We provide empirical and analytical results on the use of primary eeects. First, we experimentally demonstrate that the use of primary eeects may lead to an exponential reduction of the planning time. Second, we analytically explain the experimental results and identify the factors that innuence the eeciency of planning with primary eeects. Third, we describe an application of our analysis to predicting the performance of a planner for a given selection of primary eeects.