The document discusses several models of mass communication effects:
1. The hypodermic needle model suggests media can precisely inject ideas into passive audiences.
2. The magic bullet model from the 1940s-50s viewed media as a powerful influence on behavior change.
3. The two-step flow model proposes opinions spread from media to opinion leaders then to the public.
4. Cultivation theory argues heavy media exposure shapes viewers' perceptions of social reality.
5. Agenda-setting theory holds media influence public issues by deciding what is newsworthy.