The media effects tradition occupies a hugely influential and dominant role within mainstream communications research. It is unquestionably the longest running tradition within the field of audience studies, spanning nearly its entire history, yet it continues to divide opinion, both methodologically and with regard to its fundamental approach towards the study of media audiences. Its influence extends well beyond the academy, and the powerful influence exerted by its research agenda on public and political understanding of the impact of media is perhaps one of its most significant achievements.