Playing with Data was a four-year, NSF-funded collaboration with our partner, GlassLab, to study how to support middle-school science teachers in interpreting and using digital game-based formative assessment data to enhance student learning. In Years 1 and 2, we  worked with middle-grade science teachers to revise and expand GlassLab's online formative assessment and data-reporting dashboard. Although the dashboard can be used with a number of digital games, our study looked at a particular game designed to teach argumentation at the middle-school level. Then, in Year 3, we examined whether teachers' use of the revised data dashboard and related resources increased differentiated instruction and resulted in learning gains for students.