American high schools have never been under more pressure to reform: student populations are more diverse than ever, resources are limited, and teachers are expected to teach to high standards for all students. While many reformers look for change at the state or district level, the authors here argue that the most local contexts-schools, departments, and communities-matter the most to how well teachers perform in the classroom and how satisfied they are professionally. Their findings-based on one of the most extensive research projects ever done on secondary teaching-show that departmental...