This report from the National Academy of Education reviews large-scale, quantitative studies on teacher effectiveness and retention to identify factors related to improved student outcomes. The report pays particular attention to the role of effective clinical experiences, analyzing the effect of duration, the quality and kind of clinical experiences, field placement/student demographics, and the effectiveness of coaching teachers, on teacher effectiveness and retention. The report also reviews literature on practice-based coursework and the quantity of coursework offered. Ultimately, the studies reviewed point to participation in a clinical experience that is aligned with program dimensions, occurring in schools with a strong professional learning environment, and staffed with instructionally effective cooperative teachers who provide high-quality coaching and participation in a program with a greater amount of coursework as being linked to increased teacher effectiveness and greater teacher retention. The report ends with a series of policy and practice recommendations well suited for policymakers and teacher preparation program administrators.