Over the past 15 years, we have seen an increase in the use of cluster randomized trials (CRTs) to test the efficacy of educational interventions. These studies are often designed with the goal of determining whether a program works, or answering the what works question. Recently, the goals of these studies expanded to include for whom and under…

Teacher professional development (PD) is seen as critical to improving the quality of US schools (National Commission on Teaching and America's Future, 1997). PD is increasingly viewed as one of the primary levers for improving teaching quality and ultimately student achievement (Correnti, 2007). One factor that is driving interest in PD is…

Growing interest in teaching quality and accountability has focused attention on the need for rigorous studies and evaluations of professional development (PD) programs. However, the study of PD has been hampered by a lack of suitable instruments. The authors present data from the Teacher Knowledge Assessment System (TKAS), which was designed to…

With research indicating substantial differences among teachers in terms of their effectiveness (Nye, Konstantopoulous, & Hedges, 2004), a major focus of recent research in education has been on improving teacher quality through professional development (Desimone, 2009; Institute of Educations Sciences [IES], 2012; Measures of Effective…