"This paper reports results of the first systematic analysis of the progress of standards-based reform in U.S. school districts. Using data from a recent national survey of school districts and a companion national survey of schools, we find that not only do districts appear to play an important role, bigger districts appear to be particularly successful in promoting reform. Those who see reform as an exclusively state-school process may miss key ingredients for success. It is also a mistake to assume that large districts are not responsive. The benefits of larger size, however, appear to be moderated in high-poverty districts."