Successful middle schools do not happen by accident--they happen through leadership. Principals promote a shared vision that empowers school staffs to set high standards and continuously improve student achievement. And these middle grade educators also try to help their adolescent students see the connection between their work in school and their futures. Those are among the findings of "Gaining Ground in the Middle Grades," a landmark study by EdSource, published in 2010. EdSource interviewed nine of the 303 principals who participated in the study to learn more about how successful schools' leaders are implementing these strategies and what they've learned along the way. Each of the nine schools serves low-income students and is notable for its students' academic success.