The document discusses agenda setting theory in communication. It was developed in 1972 by Dr. Max McCombs and Dr. Donald Shaw based on the 1968 US presidential election. The core assumption of agenda setting theory is that media influences public perception of what issues are important by how frequently and prominently they cover certain issues. While media may not reflect reality directly, it filters and shapes public perception of what issues are salient. The theory focuses on how media sets the agenda for what the public thinks about through selection, emphasis, and framing of issues.