Communications research and theory has its origins in the development of the media of communication, particularly mass media. In the beginning, starting around the turn of the century, studies of mass communication were occasional exercises carried out from the traditional bases of history, law, etc. But as the social importance of mass communication increased with mass-circulated commercial press and particularly after the introduction of radio broadcasting in the twenties, this field of social communications research began to grow and take shape. First it was usually associated with particular media, like German Zeitungswissenschaft (‘Newspaper science’) or American ‘radio research.’ The latter was strongly stimulated by the market needs of rapidly expanding commercial broadcasting which in this form of audience research at the same time served as the main force to develop general public opinion surveys. Gradually, however, media-bound approaches were replaced by a more general view of the mass media; in the German area this development led between the wars to the emergence of Publizistik (‘Science of public communication’) while the concept of ‘communication research’ broke through in the American arena towards the end of the forties (significantly enough, Paul Lazarsfeld and his colleagues even changed the title of their series ‘Radio Research’ into ‘Communication Research’).