Professional learning benefits students and teachers. It helps the school meet its development priorities. Designed well, it should empower and enable success at the organisational edge, supporting everyone to best meet student, parent and community needs. Designing professional learning for impact – and measuring that impact – is much more difficult. This chapter describes the evaluation of professional learning, both at teacher and leadership level. Professional learning should be responsive, not merely delivered and parroted. The chapter provides a detailed exploration of professional learning design to get deliberative or adaptive levels of expertise. Effective professional learning requires careful facilitation with high levels of trust. In professional learning processes, the priorities are set only by senior leaders based on small snapshots of performance and highly aggregated test data. Students' friends and family can be fascinating sources of information about how their learning is going.