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…

We investigated methods of including covariates in two-level models for cluster randomized trials to increase power to detect the treatment effect. We compared multilevel models that included either an observed cluster mean or a latent cluster mean as a covariate, as well as the effect of including Level 1 deviation scores in the model. A Monte…

Language learners' productive role in teaching and learning processes has recently been the focus of attention. Therefore, this study aimed at investigating the effect of oral vs. written output-based instruction on English as a foreign language (EFL) learners' vocabulary learning with a focus on reflective vs. impulsive learning styles. To this…

When lotteries are infeasible, researchers must rely on observational methods to estimate charter effectiveness at raising student test scores. Considerable attention has been paid to observational studies by the Stanford Center for Research on Education Outcomes (CREDO), which have analyzed charter performance in 27 states. However, the…

As a result of the 1998 reauthorization of Head Start, the Department of Health and Human Services conducted a national evaluation of the Head Start program. The goal of Head Start is to improve the school readiness skills of low-income children in the United States. There is a substantial body of experimental and correlational research that has…

This "What Works Clearinghouse Procedures and Standards Handbook (Version 3.0)" provides a detailed description of the standards and procedures of the What Works Clearinghouse (WWC). The remaining chapters of this Handbook are organized to take the reader through the basic steps that the WWC uses to develop a review protocol, identify…

The central purpose of this study was to determine if teaching the subject matter of diversity or social psychology to military sponsored college students would change the level of sensitivity (behavior and attitude) to diversity as measured by an instrument called The Inventory of Cross Cultural Sensitivity developed by Kenneth Cushner (1986).…

Presents an alternative statistical test, BOOT(subscript)med for the two-group situation when a small experimental group is being compared with a large control group. BOOTmed is a between-groups median test derived through bootstrapping techniques. Empirical validation indicates that BOOTmed maintains relatively robust error rates under a variety…

This paper reports the findings of an experiment that investigated the reactions of Saudi college students to collaborative learning techniques introduced in two modalities: face-to-face and web-based learning. Quantitative data were collected with a questionnaire that examined the changes of three constructs: attitudes toward collaboration,…

The regression-discontinuity approach to evaluating educational programs is reviewed, and regression-discontinuity post-program mean differences under various conditions are discussed. The regression-discontinuity design is used to determine whether post-program differences exist between an experimental program and a control group. The difference…

A study explored which nonexperimental comparison group methods provide the most accurate estimates of the impacts of mandatory welfare-to-work programs and whether the best methods work well enough to substitute for random assignment experiments. Findings were compared for nonexperimental comparison groups and statistical adjustment procedures…