Two variables involved in attitude change provided the basis for this study, the cognitive complexity of the subject and the dimensions of stimulus materials. After a pretest, 165 interpersonal communication students were divided into two groups according to their cognitive complexity levels. The dimensions of the stimulus were presented on two levels: information that was unidimensional and information combined with three dimensions. Results indicated that subjects were most influenced by the stimulus message that fit their conceptual structure. The study concludes that both dispositional and situational factors must be considered if a maximum attitude change is expected. (Appendixes include the following: the information, the unidimensional stimulus, the combined dimension stimulus, and the rating chart used in the study. (MAI)