Considerations related to generalization of a study's findings are often interconnected to researchers' judgements regarding the 'quality' of the methodology and methodological pluralism. Too often, researchers consider generalization as only possible with respect to quantitative studies with large numbers of randomly selected participants…

External validity is an important parameter that needs to be considered for decision making in health research, but no widely accepted measurement tool for the assessment of external validity of randomized controlled trials (RCTs) exists. One of the most limiting factors for creating such a tool is probably the substantial heterogeneity and lack…

As evidence from evaluation and experimental studies continue to influence decision and policymaking, applied researchers and practitioners require tools to derive valid and credible inferences. Over the past several decades, research in causal inference has progressed with the development and application of propensity scores. Since their…

The purpose of this paper is to propose a revision of the well-known Campbellian system for causal research. The revised system, termed the COPS model, applies to both applied and basic research. Five validities are included, where two validities are adopted from the Campbellian system, and the validities are partly hierarchically ordered.…

GeoGebra is a dynamic software that is frequently used and of increasing importance in mathematics teaching processes in our digital age. Accordingly, in this study a new perspective has been brought to the proofs of the "two square difference identity" expressed for the square, which is a flat polygon, made with different approaches.…

Most social scientists agree that case studies are useful for "theory building," but ethnographic methods papers often look to survey research for case selection strategies. This is due to a common but untenable distinction between theoretical and empirical generalization, which obscures how theoretically inclined ethnographers make…

The questionnaire method has always been an important research method in psychology. The increasing prevalence of multidimensional trait measures in psychological research has led researchers to use longer questionnaires. However, questionnaires that are too long will inevitably reduce the quality of the completed questionnaires and the efficiency…

This article presents the consensus of an National Council on Measurement in Education Presidential Task Force on Foundational Competencies in Educational Measurement. Foundational competencies are those that support future development of additional professional and disciplinary competencies. The authors develop a framework for foundational…

Researchers need to know what is an appropriate sample size for interview work, but how does one decide upon an acceptable number of people to interview? This question is not relevant to case study work where one would typically interview every member of a case, or in situations where it is both desirable and feasible to interview all target…

Cross-validation is a common statistical procedure applied to problems that are otherwise computationally intractable. It is often employed to assess the effectiveness of prediction procedures. In this report, cross-validation is discussed in terms of "U"-statistics. This approach permits consideration of the statistical properties of…

Over the past 50 years, scientists have made amazing discoveries about the origins of human language acquisition. Central to this field of study is the process by which infants' perceptual sensitivities gradually align with native language structure, known as "perceptual narrowing." Perceptual narrowing offers a theoretical account of…

It's often useful extending students beyond the limiting geometry of triangles and quadrilaterals to regularly consider generalizations of results for triangles and quadrilaterals to higher order polygons. A brief heuristic description is given here of the author applying this strategy, and which led to an interesting result related to the…

Classroom observation research plays an important role in policy, practice, and scholarship for students with disabilities. When interpreting results of observation studies, it is important to consider the validity evidence provided by researchers and how that speaks to the intended use of those results. In this literature synthesis, we used…

This study sought to explore whether access to definitions and general representations influences the construction of general direct arguments. Data was collected in college mathematics courses for prospective elementary school teachers. Participant arguments were analyzed along two variables: the generality of the representations and the…

This quality review is an analysis of the methodological quality of social communication intervention research identifying which social communication interventions for this population could be considered evidence-based practices (EBPs). The purpose of the quality review was to apply the What Works Clearinghouse (WWC) guidelines to the literature…