Best-First Search

Heuristic Search ➤ Idea: don’t ignore the goal when selecting paths. ➤ Often there is extra knowledge that can be used to guide the search:heuristics. ➤ h(n) is an estimate of the cost of the shortest path from noden to a goal node. ➤ h(n) uses only readily obtainable information (that is easy to compute) about a node. ➤ h can be extended to paths: h(〈n0, . . . , nk〉) = h(nk). ➤ h(n) is an underestimate if there is no path from n to a goal that has path length less than h( ).