Search strategy which always selects the node on the frontier that has the lowest heuristic estimate of the distance to the goal node from the frontier node. A search strategy that searches concurrently forward from the start node and backward from the goal node. A strategy that first finds some path to a goal node with some cost C, then whenever it exceeds cost c when searching for other paths, it discards that path. yA search strategy that breaks up a problem into identifying an intermediate node (or a set of intermediate nodes) through which a path must pasS. 1. A search 2. Best-first search Modification to a basic search strategy in which nodes on the frontier are 3. Bidirectional searclh recomputed instead of being stored, in order to save space at the expense of computational time. 4. Branch-and-bound search 5. Dynamic programming search Modification to a basic search strategy that discards all but one path to an intermediate node when multiple paths have Heuristic depth-first-search 7. Island-driven search 8. Iterative deepening 9. 6. been found. Search backwards from the goal node, building a table of cost-to-goal(n) for each node n that is one, two, three, etc. nodes away from the goal node, until arriving at the start node Multiple-path pruning Search strategy that combines lowest-cost-first search and best-first search to always explore the node on the frontier that has the lowest estimated total cost to the goal node (the sum of the cost of the path to get to that frontier node plus the estimate of the cost from that node to the goal node) A form of depth-first search where the choice of the next node to explore is made based on the estimate of the distance from nodes on the search frontier to the goal node