In an era of high-stakes accountability under the federal No Child Left Behind Act, educators are increasingly interested in data and analysis that can effectively inform decisionmaking at the classroom, school, and district levels. The Pittsburgh Public Schools (PPS) has undertaken a districtwide effort to increase student achievement and reduce the racial gap in achievement through investment in a system to support data-driven decisionmaking. The system, known as RTI, or “Real-Time Information,” is designed to link all information about students districtwide. PPS asked RAND to assess the extent to which the RTI system could permit longitudinal statistical analysis to inform data-driven decisionmaking at the district level. Although such data easily allow an assessment of student-level trends, there was some question of whether this strength extends to the level necessary to inform policy decisions, such as analysis of the effects of programs, policies, schools, and teachers on individual, school, and district performance. Overall, the study found that, in general, the RTI system is well-suited to this purpose. However, reliable estimates require more than a well-constructed data system and the application of longitudinal statistical techniques, and assessments of growth in student achievement are complicated by the use of varying assessments in different years.