The Encyclopedia of Political Communication discusses the major theoretical approaches to the field, including direct and limited effects theories, agenda-setting theories, sociological theories, framing and priming theories, and other past and present conceptualizations. Considerable attention is devoted to major sources of political communication and to important political messages such as political speeches, televised political advertising, political posters and print advertising, televised political debates, and Internet sites. The audiences for political communications are also central, necessitating concentration on citizen reactions to political messages, how the general public and voters in democratic systems respond to political messages and the effects of all types of media and message types.