Although theoretical concepts, in principle, may be eliminated from a precise axiomatic theory, sociology practically cannot dispense with theoretical concepts. Theoretical concepts comprise structural content, i. e., their meaning is in part determined by logical-structural relationships in which they occur in general hypotheses of the theory. Consequences derived from statements of such structural character, structural implications, are illustrated by a sociometric example and by an organization-sociological one drawn from the theory of tournaments. Some statements seemingly comprising empirical content, thus, turn out to be structural implications of experimental pre-arrangements, of descriptive models or of socially valid institutional structural rules. Structural implications are either analytical implications of the experimental set-up or of the descriptive model as well as of the structural content of the theory. Sociologists should know and realize structural implications in order not falsely to take analytical deductions from the model for statements with empirical content. Concerning such methodological knowledge sociologists have to be able to avail themselves of results of philosophy of science.