Considerable controversy exists about the size and character of the Jewish population in the United States. Available sources of data about American Jewry are based on complex surveys that have become increasingly difficult to conduct. Accumulating evidence suggests that these surveys provide a misleading portrait. The goal of the present report is to identify key problems with existing socio-demographic data on American Jewry, describe a new paradigm for gathering basic data, and provide initial findings from the application of new methods.The collection of systematic socio-demographic data about American Jewry has been the focus of a set of specialized national and local studies, funded in virtually all cases by Jewish communal organizations. As part of the present assessment of existing data, this report re-examines the most prominent national study, the National Jewish Population Survey (NJPS) 2000-01, and uses it as the basis for discussing the utility of currently available information about American Jewry.