1. He was a great man; his goal was to produce himself for the future. He was associated with analyzing within two lenses of analysis, research institutes, and methodology. Paul Lazarsfeld was a founding father of empirical sociology in the 20thcentury in America. Katz and Paul Lazarsfeld both also developed of two-step Flow of Mass Communication Model. Two-Step Flow of Mass Communication Theory was developed by Paul Lazarsfeld together with Elihu Katz in writing a Book namely; 'Personal Influences'. This Book describes the reactions of common people to the media messages that are mediated by interpersonal communication with members of their social environment. The 'Two-Step Flow of Communication Model' hypothesizes those ideas flow from the mass media to 'opinion leaders' and from them to a wider audience;AIDA Model Katz and Lazarsfeld Two Step Flow Model Paul Lazarsfeld was born on February 13 -1901 in Austria and died on August 30 -1976 in the USA