Somebody asked me recently what pushes me as a professional,” says Becky Jensen, an elementary school teacher in San Jose, California. “It started when a new principal came in several years ago and let me try new strategies. But he also set up a structure to help me think through what worked and what didn’t, and then he gave me the space to lead.” A principal’s support helped Jensen become more reflective and intentional about her teaching, which in turn led her to want to help other teachers. She began by co-facilitating her grade-level team despite being among the least experienced staff members at her school. In that role, she emphasized depth over breadth: “Rather than coming up with a whole list of strategies for