Reference: Washington, R. Back to the Future: Forward Versus Backward Search for Real-Time Planning. Knowledge Systems Laboratory, December, 1992.
Abstract: Classical planning systems have favored backward search, since it has a smaller search space in many cases. Recent work on real-time planning has shifted focus towards forward planning techniques, since a forward plan will provide executable actions even when interrupted short of a complete plan. We have investigated the relative worth of incomplete forward and backward planning for the eight-puzzle, a standard search problem. Our results show that forward planning holds a statistically significant advantage over backward planning, but that the difference is so small that it is secondary to other factors.
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