Agenda-setting theory suggests that the communications media, through their ability to identify and publicize issues, play a pivotal role in shaping the problems that attract attention from governments and international organizations, and direct public opinion towards specific issues. The theory suggests that the media can shape public opinion by determining what issues are given the most attention, and has been widely studied and applied to various forms of media. The way news stories and topics that impact public opinion are presented is influenced by the media. It is predicated on the idea that most individuals only have access to one source of information on most issues: the news media. Since they establish the agenda, they may affect how important some things are seen to be.
The agenda-setting by media is driven by the media's bias on things such as politics, economy and culture, etc. Audiences consider an issue to be more significant the more media attention it receives (issue saliency). For instance, even if readers don't have strong feelings about immigration, they will believe that it is a pressing problem at the time if there is consistent journalistic coverage of it over the period of a few months.
