A key lever for improvement in instruction and student support is the data that are available in urban districts. A considerable amount of information now exists about students' academic strengths and weaknesses, and the momentum to build and improve data systems is increasing at a rapid pace. In fall 2008, the Council of the Great City Schools and the American Institutes for Research launched a project funded by the Bill & Melinda Gates Foundation focused on understanding and improving the use of interim assessment data as a catalyst for instructional improvement. The overarching goal of this study is to establish principles of "best practice" in using interim assessment data to improve instruction and target support. This report shares findings to date that address the first objective: to document current practices of urban school districts in regard to interim assessments, data systems, and the use of data for decision making. The findings draw from two sources of information. The first source comprises surveys administered in summer 2009 to Curriculum Coordinators and Research Directors in the member districts of the Council of the Great City Schools about their use of interim assessments and data systems. The data from this survey provide a general overview of the state of current practice in using data to inform school- and classroom-level decision making across U.S. urban districts. The second is a set of case studies based on site visits to four selected urban districts between February and April 2010. (Contains 7 exhibits and 2 footnotes.)