Knowledge-based approaches to media priming effects

In the area of political communication, media priming effects have been tested and illustrated by the phenomena that exposure to salient issues enhances the weight of issue performance approval with regard to the general performance approval of the president. However, the process underlying why and how this happens has not been fully examined. One of the main goals of this study was to propose and test the potential mechanisms of media priming effects, which will hopefully address the theoretical lacuna in current priming research.; The present study proposed two models. The first is based on issue specific learning from media exposure. The second uses a projection model to explain the media priming process. For the learning models, issue learning was introduced as a mediating mechanism to account for media priming effects. This mediating process could happen through two different routes---learning based media priming route and learning based persuasion route. Finally, the projection model argues that people rely on their pre-held opinions about the president. That is, media cues enhance the motivation of internal consistency, which causes people to adjust their issue approval to be consistent with their pre-existing overall opinion about the evaluative target.; Among the three models that could explain media priming, only the projection model was fully supported by the data in this study. Despite some indication of issue learning, this did not affect the relationship between issue approval and the overall performance approval. However, the result indicated the existence of the projection effect. Current issue approval on the primed issue was critically influenced by the premeasure of overall performance approval of the president, especially among those who watched newscasts about the primed issues.; The second goal of the present study was to emphasize the importance of issuespecific knowledge in media priming research. Results showed that there was only a borderline moderating effect of general political knowledge in media priming. Moreover, this borderline moderating effect of general political knowledge became insignificant when issue knowledge was controlled.; On the other hand, the issue knowledge measure moderated the media priming effects after controlling the general political knowledge. Although the types of issue knowledge that moderated the media priming effects varied depending on the issue, the pattern persisted nonetheless. People with more issue knowledge showed stronger media priming effects in both issue areas. This finding is explained by the applicability thesis, which suggests that issue knowledge is a more appropriate type of knowledge with respect to the moderating effects of knowledge in media priming.