This study examined bias reduction in the eight nonequivalent comparison group designs (NECGDs) that result from combining (a) choice of a local versus non-local comparison group, and analytic use or not of (b) a pretest measure of the study outcome and (c) a rich set of other covariates. Bias was estimated as the difference in causal estimate…

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…

This review describes a meta-analysis of findings from 50 controlled evaluations of intelligent computer tutoring systems. The median effect of intelligent tutoring in the 50 evaluations was to raise test scores 0.66 standard deviations over conventional levels, or from the 50th to the 75th percentile. However, the amount of improvement found in…

To answer "what works?" questions about policy interventions based on an experimental design, Peck (2003) proposes to use baseline characteristics to symmetrically divide treatment and control group members into subgroups defined by endogenously determined postrandom assignment events. Symmetric prediction of these subgroups in both…

Experimental and quasi-experimental designs are used in educational research to establish causality and develop effective practices. These research designs rely on a counterfactual model that, in simple form, calls for a comparison between a treatment group and a control group. Developers of educational practices often assume that the population…

This study explores the extent to which differences in research design explain variation in Head Start program impacts. We employ meta-analytic techniques to predict effect sizes for cognitive and achievement outcomes as a function of the type and rigor of research design, quality and type of outcome measure, activity level of control group, and…

Early detection methods for autism spectrum disorder (ASD) in infancy are rapidly advancing, yet the development of interventions for infants under two years with or at-risk for ASD remains limited. In order to guide research and practice, this paper systematically reviewed studies investigating interventions for infants under 24 months with or…

The researcher employed two designs to address the research question for this particular study. This quasi-experimental non-equivalent control group study compared the math achievement of 92 eighth grade students who received Classroom Performance System (CPS)-based instruction using Peer Instruction (PI) to 76 eighth grade students who received…

Using exogenous characteristics to identify endogenous subgroups, the approach discussed in this method note creates symmetric subsets within treatment and control groups, allowing the analysis to take advantage of an experimental design. In order to maintain treatment--control symmetry, however, prior work has posited that it is necessary to use…

Evaluations should be issues driven, not methods driven. The starting point should be priority programs to be evaluated or policies to be tested. From this starting point, a list of evaluation questions is identified. For each evaluation question, the task is to identify the best available method for answering that question. Hence it is likely…

The current study examined whether adding emancipatory sexuality education, which encourages the exploration of women's own sexual values and desires, to a sexual assault resistance program would improve women's resistance to sexual assault by known men. The participants were 214 first-year university students. A randomized experimental design…

Purpose: The purpose of the paper is to present evidence on the impact of enterprise education on young people still at school in London, UK. The study was designed to measure the effect of participation in a Young Enterprise (YE) Company Program on young people's attitudes toward starting a business, and on their enterprise potential.…

This report describes a cluster randomized control trial (RCT) intervention study of the effectiveness of the ABRACADABRA (ABRA) Web-based literacy system using a classroom-level RCT intervention with 1,067 children in 74 kindergarten and Grade 1 or Grade 1/2 classrooms across Canada. The authors closely followed the CONSORT criteria for executing…

Developmental summer bridge programs are a popular strategy for increasing college readiness among recent high school graduates. Aimed at providing an alternative to traditional developmental education, these programs provide accelerated and focused learning opportunities in order to help students acquire the knowledge and skills needed for…