The role of principals in student achievement is an important factor, not only in the evaluation context, but also in education policy and reform discussions. While research on the topic is not limited, more and more studies are being undertaken as public policy is tying student achievement to principal evaluations. School principals have a strong effect on student achievement, in creating conditions and cultures that lead to better teaching and learning and on shaping the long-term impact of school improvements. The results of a study on the impact of principal effectiveness were recently published in Education Next, a journal coproduced by the Hoover Institute (Stanford University),