“I became obsessed with how to develop great teachers,” she said.

The first step in that complex, difficult process is to create a school environment that has standards high enough and challenging enough to appeal to very good people. “You put all of your focus on finding great people,” said Ms. Kenny, “and you establish a culture that helps them constantly learn and grow and become better at what they do. You have to provide a community in the school that supports and respects teachers. And you have to give them the kind of freedom that allows their passion for teaching to flourish.

“We’ve created a culture that brings out the passion of the teachers and they bring out the passion of the kids.”