The document summarizes several media theories: 1) The Hypodermic Needle Theory suggests that mass media can directly influence large groups of people uniformly by delivering targeted messages to trigger desired responses. An example was the 1938 "War of the Worlds" radio broadcast that caused a panic. 2) The Inoculation Theory proposes that exposing people to weak arguments beforehand makes them more resistant to stronger persuasive messages later. 3) The Two Step Theory argues that media information moves in two stages - first to opinion leaders who then pass on their own interpretations to influence others they are similar to.