Background/Context: Observational studies often employ regression discontinuity (RD) designs and multiple control-group designs to explore the causal quantities of interest. RD designs assess policy and program effectiveness by assigning subjects to treatment based on whether they exceed a pre-defined cutoff. RD designs are classified into two…

Background/Context: Some observational studies involve multiple layers of treatment selection, specifically in the context of the extended time accommodation (ETA) for English language learners (ELLs). In ETA settings, the first selection occurs due to the eligibility rule, where students whose ELL English proficiency is below a certain threshold…

Background: Over the past 20 years, much has been written about the merits and limitations of matching methods, particularly propensity score matching (see, e.g., Stuart, 2010 for a review of matching approaches), and the myriad ways matching can be implemented to identify a comparison group that is similar to the treatment group on observable…

Ratio and proportional relationships, along with the interrelated topics of fractions,decimals, and percent, provide a critical foundation for algebra (National Mathematics Advisory Panel, 2008). Proportional reasoning, which not only requires understanding the concept of ratios and that two or more ratios are equal, also requires the ability to…

The purpose of this paper is to showcase new research that seeks to provide guidance on the heterogeneity of treatment effects by utilizing the variance of demographic differences in state assessments. This study is focused on a simple randomized block design where students are nested within schools, and within each school students are randomized…

Questions regarding the generalizability of results from educational experiments have been at the forefront of methods development over the past five years. This work has focused on methods for estimating the effect of an intervention in a well-defined inference population (e.g., Tipton, 2013; O'Muircheartaigh and Hedges, 2014); methods for…

Recent federal legislation, such as the "No Child Left Behind Act" of 2001 and the "Education Sciences Reform Act (ESRA)" of 2002, has insisted that educational evaluations use rigorous research designs with quantitative outcome measures. In particular, the Institute of Education Sciences (IES) at the U.S. Department of…

A cluster-randomized trial (CRT) relies on random assignment of intact clusters to treatment conditions, such as classrooms or schools (Raudenbush & Bryk, 2002). One specific type of CRT, a multi-site CRT (MSCRT), is commonly employed in educational research and evaluation studies (Spybrook & Raudenbush, 2009; Spybrook, 2014; Bloom,…

One approach to reducing persistent racial/ethnic achievement gaps is to tackle their social-psychological dimensions, including the negative consequences of stereotype threat and other identity threats in school. Initial research suggested that a particularly promising approach is brief self-affirmation writing exercises for 7th grade students;…

Most research on the middle school transition focuses on developmental and psychological changes around the age of the transition, and investigates or discusses the impact of such changes on academic performance, motivation and behavior in schools. In addition to intrapersonal developmental changes that middle-school students experience, they also…

In recent years, the regression discontinuity design (RDD) has gained widespread recognition as a quasi-experimental method that when used correctly, can produce internally valid estimates of causal effects of a treatment, a program or an intervention (hereafter referred to as treatment effects). In an RDD study, subjects or groups of subjects…

The capacity of the field to conduct power analyses for group randomized trials (GRTs) of educational interventions has improved over the past decade (Authors, 2009). However, a power analysis depends on estimates of design parameters. Hence it is critical to build the empirical base of design parameters for GRTs across a variety of outcomes and…

This paper provides causal evidence to answer the question, "Does the application of a double dose of literacy instruction in middle school improve student performance on subsequent academic outcomes?" The focus of this paper is on an intervention where the second dose of literacy instruction uses research-based instructional strategies,…

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…