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…

Many school systems are adopting new curricula in response to more rigorous standards that require higher-order thinking skills. This chapter presents implementation findings from a randomized, controlled trial of the Cognitive Tutor Geometry curriculum. We found a significant negative effect on student achievement despite the curriculum's focus…