The federal No Child Left Behind Act and its mandate for adequate yearly progress has placed unprecedented demands on districts to use evidence to support their school improvement efforts. Research has not yet determined if data-driven decision making leads to improvements in teaching and learning since most outcomes reported to date are based on case studies offering anecdotal evidence. This information capsule discusses the use of data-driven decision making in the nation's schools, research findings on the effects of data-driven decision making, including factors that may facilitate the data-driven decision making process, and the challenges associated with implementing data-driven decision making. A summary of some of Miami-Dade County Public Schools' initiatives that utilize data-driven decision making, professional development opportunities offered by the district, and online systems that provide staff with access to data is also included. (Contains 7 online resources.)