9320704 McPhail This is a study of the reliability of mass media reports of collective action events in Washington D.C., and the development of an expanded data base to allow comprehensive social-scientific analysis of the biases in media reporting. The project has five related aims: to add city permits and media records of demonstrations from 1973 to the existing data set; to code the content of all media traces for analyses of description bias; to expand the analysis of media bias by developing multiple methods for comparing media reports with systematic observations; to assess implications of the findings for improving attempts to limit researcher bias; and to explore the possibilities of studying the national and international diffusion of the National Park Service permit system. %%% This research contributes to political sociology and to the development of scientific methodology for studying public demonstrations and their handling by the mass media. It therefore will greatly strengthen social-scientific research on important aspects of democracy that lie outside the system of parties and elections. Results will be of direct value for political leaders who need to understand the meaning of public demonstrations and for journalists who need to upgrade the accuracy of their reporting. ***