The current high-stakes accountability environment has created strong incentives for educators to systematically collect and use data to inform instructional decisions. This article examines the strategies employed by three urban school districts to promote data use for instructional improvement and their effect on administrator, principal, and teacher practice. Several factors are found to affect data use, including accessibility and timeliness of data, perceptions of data validity, training, and support for teachers with regard to data analysis and interpretation, and the alignment of data strategies with other instructional initiatives.