Haviv Rettig Gur writes about how the latest community study of New York Jewry, by the UJA-Federation of New York has broken new ground in the complicated art of studying American Jews. By sampling an unprecedented 6,000 households, asking new kinds of questions about religious practice, and focusing on areas with low rates of affiliation alongside the more concentrated Jewish communities, the study has for the first time offered local Jewish organizations and community planners new tools for tackling questions of identity, engagement, poverty and education.