1. Introduction - Foundation of Communication Research

2. Austrian Radio Audience Research - Paul Lazarsfeld's RAVAG Report

3. Princeton Radio Project - The Leading Project in the Beginnings of Mass Communications Research

4. Attitude Formation Research, Panel Study Method and Opinion Leaders Discovery

5. Mass Communication and Interpersonal Communication - Two Main Topics

6. Two-step Flow of Communications Hypothesis and its Counterparts. His Master’s Voice by Elihu Katz

7. Mass Media Influence: Invasion from Mars - A Study of Panic Created by a Radio Broadcast and Study of Mass Persuasion - War Bond Drive

8. Influentials and Types of Influentials (Local and Cosmopolitan Influentials)

9. Interpersonal Communication and Interpersonal Influence

10. Methods of Studying Opinion Leadership

11. Personality Strength Scale - A Method for Opinion Leaders Identification

12. International Communication On-line Research