Imitation is a semantic scheme for observing social behaviour. Its function lies in the control of conformity and deviance on the basis of similarities with given model and thus provides orientation for social expectations. However, not all similarities presuppose imitative contacts but may be the outcome of convergent developments despite different starting conditions. Furthermore, functional equivalents may serve as substitutes for imitation. For example, persons or artifacts can be exempted from either imitating or being imitated if they are considered to have a unique and incomparable quality. The semantics of imitation vary historically and thus provide also information about changes in practices of imitation and their social value.