ABSTRACT
Most of the research described in previous chapters of this book involved an examination of what happens to one's opinions after a persuasive message on some topic has been encountered. Sometimes the messages come from external sources, and sometimes (as in the active participation experiments described in Chapter 1) the person constructs his or her own communication. But in each case, the focus is on what happens after the communication has been received. The work to be covered in the present chapter, however, involves a different question: What are the effects of simply expecting to have to deal with a persuasive communication? For example, if the President of the United States wanted to convince the public that taxes should be raised, would he be more effective if the public were forewarned of his position, or if his message took them by surprise?
