1. a graphical representation used to characterize game playing and other search-based problem solving. A state space has four components: (a) a set of nodes or states, (b) a set of arcs linking subsets of the nodes, (c) a nonempty set of nodes indicated as the start nodes of the space, and (d) a nonempty set of goal nodes of the space. The goal nodes are identified by either a property of the state itself (e.g., a checkmate) or a property of the path leading to the goal state (e.g., the shortest path). An architecture such as a production system or classifier system can generate a state-space search. Computational state-space analysis and computer simulations of problem solving often are used as well in the study of how people pursue goal-directed behavior. See also graph; search; tree.

2. multidimensional space, particularly as related to the depiction of the results of classification methods used to group objects with similar characteristics and patterns of behavior.