This chapter discusses several questions that plague those who start from the premise that research should inform practice: Why hasn’t research had greater impact on education in general, and the practice of school psychology in particular? How might research have greater impact on the practice of school psychology? And what research has influenced practice and why? The chapter describes important educational or psychoeducational research has influenced the practice of school psychology. Developmental/clinical research that has influenced the practice of school psychology stems from two quite distinct directions. One line comes from research that interacted with or followed from social policy decisions. The other line comes from basic research and theory originally developed in an academic setting. Research on effective teaching has increased greatly in quantity and quality. If all social science research is viewed as having potential impact on education, there is too much to be aware of, to integrate, and to assimilate.