Topic outline
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Search algorithms play a huge role in AI. GPS, for example, is all about searching for some solution or optimal solutions in a large solution space, often described as a tree. This unit will discuss various search algorithms that can be utilized in many different situations.
Completing this unit should take you approximately 4 hours.
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The simplest search algorithms are "uniformed" or brute-force search. Different algorithms, such as depth-first, breadth-first, and uniform cost search, fall into the uninformed category because there is no knowledge, insight, or hint about where the right solution might lie.
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In contrast to uninformed search, informed search methods use insights or "heuristics" about where the optimal solution may lie in a complex solution space. Heuristics can be used to narrow the search. Examples of informed search algorithms include A*, also called Dijkstra's method. This section describes the key idea of the admissible heuristic that makes A* the optimal search algorithm, although still exponential. Many properties of admissible heuristics will be provided to guide you in finding these heuristics in other problems.