Surprisingly, there are few rigorous causal evaluations that can help inform teacher educators and policymakers as they design effective teacher preparation and ongoing professional development. In this session, Prof Dr Stuart Kime (EBE) and Dr Zid Mancenido (Harvard Graduate School of Education and EBE Advisory Board) discussed findings from a recent experiment aimed at providing some initial answers. They also discussed perspectives on how we can get more rigorous evaluations conducted within teacher preparation contexts, to help advance more effective teacher learning at scale.