Teacher effectiveness varies substantially, yet principals' evaluations of teachers often fail to differentiate performance among teachers. We offer new evidence on principals' subjective evaluations of their teachers' effectiveness using two sources of data from a large, urban district: principals' high-stakes personnel evaluations of teachers,…

Over the past 2 years, educational policy makers have focused much of their attention on issues related to teacher effectiveness. The Obama Administration has made teacher evaluation and teacher quality a central feature of many of its educational policies, including Race to the Top (RTTT), Investing in Innovation (i3), and the Teacher Incentive…

Scholars have long argued that principals should be "instructional leaders," but few studies have empirically linked specific instructional leadership behaviors to school performance. This study examines the associations between leadership behaviors and student achievement gains using a unique data source: in-person, full-day…

Value-added models in education research allow researchers to explore how a wide variety of policies and measured school inputs affect the academic performance of students. Researchers typically quantify the impacts of such interventions in terms of "effect sizes", i.e., the estimated effect of a one standard deviation change in the…