Pages 1-9 are missing Subjects The subjects in this experiment vrere 172 intrcductory psychology students at the University of Massachusetts who received course credit for their participation. Desif^n The study employed a3x2x2x2 before-after design involving three response sets ( role-plajdng, communicating and passive reception), proattitudinal vs. coxinterattitudinal message, high vs^, la-: communicator credibility, and message contents advocating special or general education. All manipulations and measurements were accamr^lished vdthin a single experimental session. Equal numbers of Ss were randomly assigned to receive the three resr^onse sets, high or low credibility sources, and messages advocating special or general education. Because Ss' own positions on the attitudinal issue viere not kno'-m to the experimenter -until the session was completed, the identity and number of Ss forvhom the message was pro-and counterattitudinal were not experimentally controlled.