The use of data-based decision making (DBDM) in schools to drive educational improvement and success has been strongly promoted by educational experts and policymakers, yet very little is documented about the actual DBDM practices used in schools. This study examines DBDM practices in 25 middle schools through 80 standardized observations of data team meetings and through survey responses. DBDM practices in terms of structure, process, content, quality, and alignment between self-report and observation are described. Key findings include the following: (a) The average amount of time spent discussing an individual student was brief, less than 2 min; (b) on average, actionable decisions following discussions of behavior or reading issues were made 34% to 40% of the time; and (c) there was weak alignment on key topics between self-reported and observed DBDM practices. These findings underscore the need for additional studies of DBDM practices in school and of the impact of DBDM practices on important student outcomes.