The document discusses data-driven decision making (DDDM) in education. It defines DDDM as systematically collecting, analyzing, and interpreting data to inform practices and policies. True DDDM considers more than test scores, exploring student well-being and feedback from the school community. The document also outlines the benefits of DDDM and provides examples of how teacher leaders can foster a culture of DDDM by dedicating time for collaboration, building understanding of data analysis, and working with colleagues to use data to identify problems and solutions.