Across the United States, there are schools whose students are significantly outperforming and out-improving those from nearby schools. In almost any geographic location in America, within a 30-minute drive there exist schools where classrooms are alive with stimulating learning, day in and day out. These are places where students — and adults — are thriving, where we would be thrilled for our own children and grandchildren to attend. And not too far away from these schools are schools that are none of these things. In these schools, where the adults may be working extremely hard, change is elusive, as practices stay consistent and results are stagnant. One key variable that explains the difference between these two sets of schools is leadership — highly competent principals