Without Paul F. Lazarsfeld the social sciences would not be what they are today. In his ground-breaking work on unemployment, voting, consumer behavior, and social influence, among other subjects, his methodological emphasis on vigorously controlled scientific language and structures transformed social research worldwide. Lazarsfeld's systematic criticism of observational, conceptual, and inferential procedures in sociology led to the the formation of universally applied observational and analytical techniques, such as the panel design of observation and contextual and multivariate analysis. His methodology for empirical social research had a profound effect on all the social sciences. The eighteen essays in On Social Research and Its Language illustrate the diversity of Lazarsfeld's substantive, methodological, and organizational interests. Spanning the years 1933 to 1972, they encompass his own works of social research, as well as writings on methodology and the history and sociology of social research. Articles on methodology--observing, classifying and building typologies, analyzing the relations between variables, qualitative analysis, and macrosociology--form the bulk of the book. In addition, Raymond Boudon provides a revealing biography of Lazarsfeld and his influence on sociology. These classic writings by a formative figure of modern social science will be an indispensable reference for scholars across the historical and social science disciplines.