How can media shape public opinion? 

Public opinion, an aggregate of the individual views, attitudes, and beliefs about a particular topic, expressed by a significant proportion of a community. Some scholars treat the aggregate as a synthesis of the views of all or a certain segment of society; others regard it as a collection of many differing or opposing views. Writing in 1918, the American sociologist Charles Horton Cooley emphasized public opinion as a process of interaction and mutual influence rather than a state of broad agreement. The American political scientist V.O. Key defined public opinion in 1961 as “opinions held by private persons which governments find it prudent to heed.” Subsequent advances in statistical and demographic analysis led by the 1990s to an understanding of public opinion as the collective view of a defined population, such as a particular demographic or ethnic group.