Experimental studies are often employed to test the effectiveness of teaching innovations such as new pedagogy, curriculum, or learning resources. This article offers guidance on good practice in developing research designs, and in drawing conclusions from published reports. Random control trials potentially support the use of statistical…

Treatment effect estimates from a "regression discontinuity design" (RDD) have high internal validity. However, the arguments that support the design apply to a subpopulation that is narrower and usually different from the population of substantive interest in evaluation research. The disconnect between RDD population and the…

We present an aggregation scheme that increases power in randomized controlled trials and quasi-experiments when the intervention possesses a robust and well-articulated theory of change. Intervention studies using longitudinal data often include multiple observations on individuals, some of which may be more likely to manifest a treatment effect…

In some studies, participants are assigned ethnographic or communicative tasks, such as field-work observation, life-story interviews, and photography. These studies usually involve in-person interaction, both for the participants doing the task and for the researchers in engaging with participants throughout the research process. Our study was…

In the past few decades, we have seen a rapid proliferation in the use of quasi-experimental research designs in education research. This trend, stemming in part from the "credibility revolution" in the social sciences, particularly economics, is notable along with the increasing use of randomized controlled trials in the strive toward…

In experimental research, internal validity refers to what extent researchers can conclude that changes in dependent variable (i.e. outcome) are caused by manipulations in independent variable. The causal inference permits researchers to meaningfully interpret research results. This article discusses (a) internal validity threats in social and…

Regression discontinuity design (RD) has been widely used to produce reliable causal estimates. Researchers have validated the accuracy of RD design using within study comparisons (Cook, Shadish & Wong, 2008; Cook & Steiner, 2010; Shadish et al, 2011). Within study comparisons examines the validity of a quasi-experiment by comparing its…

Identifying effective literacy interventions for teachers of very young children is important, but it is not easy. In this case study, we share our experiences implementing a quasi-experimental evaluation of an early literacy program. We describe the design and context of the study and discuss three key issues that we encountered with data…

We present a case study of the process through which a methodology was developed and applied to a quasi-experimental research study that employed propensity score matching. Methodological decisions are discussed and summarized, including an explanation of the approaches selected for each step in the study as well as rationales for these…

Our target article (Robinson-Cimpian, Lubienski, Ganley, & Copur-Gencturk, 2014) used nationally representative data to examine the development of gender gaps in math achievement. We found that when boys and girls demonstrate equivalent math test performance and are perceived by their teachers to be equally well behaved and engaged with the…

Studies of the effects of class attendance on class performance typically are quasi-experimental because students choose whether or not to attend class; that is, the samples are self-selecting. The lack of random assignment prevents one from establishing a causal relationship between attendance and performance. Relating attendance to performance…

The dominant approach to research in learning disabilities utilizes experimental and quasi-experimental designs to identify the most effective instructional strategies for students with learning disabilities. Research is always undertaken from a point of view, yet the discourse on "what works?" is generally silent on how theoretical frameworks…

Background: Mentoring has drawn substantial interest from policymakers, intervention theorists, and those interested in identifying promising and useful evidence-based approaches to interventions for criminal justice and child welfare outcomes (Grossman & Tierney, 1998; Jekliek et al., 2002). Mentoring is one of the most commonly-used…

The studies in this special section of the "Journal of Educational Psychology" present a variety of social-psychological interventions across large numbers of classrooms and populations. They show notable benefits for many students at risk for low performance. This is the glass half-full interpretation, and we consider the strengths of…

Organizational and applied sciences have long struggled with improving causal inference in quasi-experiments. We introduce organizational researchers to propensity scoring, a statistical technique that has become popular in other applied sciences as a means for improving internal validity. Propensity scoring statistically models how individuals in…