Until now, the conventional approach using two distinct groups, experimental and control, continues to dominate research, especially education research. Researchers, particularly those who are active in this domain, readily recognise this pattern when surveying literature. This article explores the use of the Solomon four-group design as a…

The randomized control trial (RCT) is the primary experimental design in education research due to its strong internal validity for causal inference. However, in situations where RCTs are not feasible or ethical, quasi-experiments are alternatives to establish causal inference. This paper serves as an introduction to several quasi-experimental…

Group design research studies can provide evidence to draw conclusions about "what works," "for whom," and "under what conditions" in special education. The quality indicators introduced by Gersten and colleagues (2005) have contributed to increased rigor in group design research, which has provided substantial…

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…

Context: Assessments of baseline equivalency of intervention and control groups, "balance," play a critical role in evaluating educational interventions. The highest What Works Clearinghouse (WWC) of the Institute of Educational Studies (IES) standard for educational studies, "Meets WWC Design Standards Without Reservations,"…

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…

Randomized control trials are considered the gold standard for conducting research and estimating causal effects; however, educational research rarely lends itself to experimental design and true randomization. In recent years, there has been a growing interest in finding new approaches to estimate causal effects in nonrandomized studies in…

Over many decades, educators have developed countless interventions and theories about how to create lasting change. Implementation research is the study of these efforts with a set of basic questions: What are we doing? Is it working? For whom? Where? When? How? And, Why? In other words, implementation research is an endeavor to understand if and…

This study investigated the effects of the use of Augmented Reality (AR) on the academic performance of students, as well as perceptions that were following the use of this new technology resource. The participants were students of primary education in Spain, which were assigned to an experimental group and a control group. Contents related to the…

E-learning research is plenty of difficulties, as also research in education is. Usually, the high number of features involved in e-learning processes complicates and masks the identification and isolation of the factors which cause the expected benefits, when they exist. At the same time, a bunch of threats are ready to weaken the validity of the…

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 article provides two illustrations of some of the factors that can influence findings from pre- and post-test research designs in evaluation studies, including regression to the mean (RTM), maturation, history and test effects. The first illustration involves a re-analysis of data from a study by Marsden (2004), in which pre-test scores are…

Experimental evaluations that involve the educational system usually involve a hierarchical structure (students are nested within classrooms that are nested within schools, etc.). Concerns about contamination, where research subjects receive certain features of an intervention intended for subjects in a different experimental group, have often led…

Given the importance of early mathematics instruction and curricula for preventing mathematics difficulties in later grades, it is necessary to identify effective mathematics curricula and instruction to ensure that children become proficient in early mathematics content and procedures. Everyday Mathematics (EM), was reviewed by the What Works…

The goal of this research is to make sensitivity analysis accessible not only to empirical researchers but also to the various stakeholders for whom educational evaluations are conducted. To do this it derives anchors for the omitted variable (OV)-program participation association intrinsically, using the Love plot to present a wide range of…