School data as mediators in professional development

International research documents a variety of approaches for fostering the professional development of principals. These studies mainly draw upon survey and interview data. Less attention has been paid to observing professional development processes. This article aims to examine how professional learning is played out empirically in the interactions among members of a school improvement team in a Norwegian context by paying special attention to school data as the departure for professional development of principals. Cultural Historical Activity Theory frames the analysis. The findings suggest that video clips of teaching practices stimulate engagement among team members and, hence, mediate professional learning processes beyond the situations presented in the workshops. These video clips triggered analyses of how to understand and improve teaching practices. In addition, external facilitation seemed crucial for anchoring the analysis theoretically, and for highlighting implications for leadership in the workshops.