Principals are the second-largest school-based contributor to K-12 students' academic progress. However, there is little research evaluating whether efforts to develop principals' skills improve school effectiveness. We conducted randomized controlled trial studies of the impacts of a professional development program called the Executive…

We use data from one of the few states where information on curriculum adoptions is available--Indiana--to empirically evaluate differences in performance across three elementary-mathematics curricula. The three curricula that we evaluate were popular nationally during the time of our study, and two of the three remain popular today. We find large…