To be useful to teachers and school leaders, test data must provide more than just a destination. Student performance results must also provide guidance that informs educators that they are moving in the right direction, while providing interactive and recursive feedback for mid-course adjustments. In order for student performance data to be useful to teachers and school leaders, and to make it worthwhile for them to make the extensive efforts necessary to learn to interpret and act upon what they learn, data feedback systems must rely on multiple sources of data collected and analyzed at regular intervals. This report is about building better roadmaps for teachers and school leaders in order to guide their instructional decision-making. The data required for more precise decision-making come from systematically exploiting a variety of student performance data at both the individual classroom and school levels. Rather than just relying on one individual test to provide guidance, innovative school leaders are building more comprehensive systems of assessments that provide better interim information from multiple perspectives. Through more sophisticated data systems, teachers and school leaders can foster a more inquiryoriented approach that involves ongoing and sustained investigations into the kinds of teaching that produce more powerful student learning. In this report, we show how innovative teachers and school leaders are creatively using their data to help guide their strategic decisions. Through their examples, we develop and describe a theory of what a system of school data use might look like.