Discussions of agent interactions frequently characterize behavior as "coherent," "collaborative," "cooperative," "competitive," or "coordinated." We propose a series of formal distinctions among these terms and several others. We argue that all of these are specializations of the more foundational category of "correlation," which can be measured by the joint information of a system. We also propose "congruence" as a category orthogonal to the others, reflecting the degree to which correlation

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... nd its specializations satisfy user requirements. Then we explore the degree to which lack of correlation can arise purposefully, and show the need to use formal stochasticity in cases where such lack of correlation is truly necessary (such as in stochastic search).