An introduction to one methodological approach potentially useful for research on persuasive communications is given. The paper presents concepts relevant to one of the most pervasive and difficult problems in persuasive communications namely, the criterion or effects problem. A method of classifying communications content based on a conceptual analysis of effects is suggested -a schema which may be useful even if communications effects cannot be assessed by the criterion measures described. The paper first deals with a means of developing persuasive appeals that might be used applied scientists of an engineering bent. This is followed by a discussion of a pragmatic theory of communication recently introduced by Russell L. Ackoff which presents human communication as a purposive activity that can be measured in terms of the decision problems of the recipient. Specific measures developed by Ackoff are described along with references to sources which present their derivation and development. Finally, directions for possible future research are discussed.