When visitors tour the authors' classrooms at the J. Erik Jonsson Community School, a 3-year-old through 5th-grade laboratory school just south of downtown Dallas, Texas, they sense that something is different. Visitors remark about the respectful, caring environment of the school and the high-powered instruction, and they want to learn how they can implement these qualities in their own schools. As part of the research, professional learning, and leadership team at the Jonsson School, the authors regularly share the work of the Jonsson School with other educators and communicate Jonsson's simple success formula: Powerful pedagogy + trusting relationships = student engagement for learning. In fall 2006, they grew curious about what the teachers were actually doing in the classroom to elicit this powerful student engagement. They hypothesized that if they could develop a way to collect evidence about student engagement in classrooms and share that evidence with their teachers, they would begin to transform their practices based on what they were learning about their students. The authors' supposition was supported by NSDC's Standards for Staff Development Data-Driven standard, which reminds them that "the study of such [classroom] evidence is itself a potent means of staff development" (NSDC, 2001). The authors asked many questions. Their questions became the classroom research during the school year 2006-07, and the data and dialogue with participating teachers created a startling exchange of evidence and resulted in changes in teacher practices.