# [Uninformed](Uninformed.md) - Breadth First - Uniform Cost - Depth First - Depth Limited - Iterative Deepening - Bi-directional ## Characteristics - Goal-led - No information on # steps - General purpose - Weak - Optimal - Exact # [Informed](Informed.md) - Best First - Greedy - Route Planning - A* ## Characteristics - Knowledge used to limit # possibilities - Intelligent heuristic methods - May give sub-optimal / wrong results # Exhaustive - All possibilities # Evaluation - Completeness - Guaranteed to find a solution? - Time Complexity - How long? - Space Complexity - How much memory? - Optimality - Is solution the best solution? # Queuing - Search strategy dictates which nodes on frontier to expand in which order - Easiest to implement as a queue - Breadth first - New nodes to back of queue - Depth first - New nodes added to front of queue - Likely need to use recursion - Uniform cost - Nodes added to queue in order of lowest cost first # Abstraction - Remove superfluous information - Represent problem in ***state space*** - States reachable from initial state by actions is ***path*** ![](../../img/searching-graph.png) ![](../../img/searching-graph-tree.png)