In the past decade, the federal government and influential scholars have argued for stronger research into the impact of educational interventions, particularly those intended to improve instructional quality (Confrey & Stohl, 2004; Raudenbush, 2008; Shavelson & Towne, 2001). Such efforts typically focus on programs of teacher professional development, improvements in the materials that guide instruction, or both. We plan to conduct a research synthesis of studies that investigate the impact of professional development and instructional improvement programs.