The biographies in the International Encyclopedia of the Social Sciences (including those in this supplementary volume), like those in the Dictionary of Scientific Biography, are of enormous use individually, but they are of uneven utility for prosopographical purposes. For example, some biographers do not provide sufficient data on employment and research activities to make systematic career line analysis possible; others make almost exclusive use of the publications of their subjects as sources and thus omit much of the information about the setting of their subjects work which a historian or a sociologist of science would prefer. But they all provide a glimpse of one member of an important generation of social scientists.