Popular item response theory (IRT) models are considered complex, mainly due to the inclusion of a random factor variable (latent variable). The random factor variable represents the incidental parameter problem since the number of parameters increases when including data of new persons. Therefore, IRT models require a specific estimation method…

The product Bayes factor (PBF) synthesizes evidence for an informative hypothesis across heterogeneous replication studies. It can be used when fixed- or random effects meta-analysis fall short. For example, when effect sizes are incomparable and cannot be pooled, or when studies diverge significantly in the populations, study designs, and…

American Educational Research Association (AERA) standards stipulate that researchers show evidence of the internal structure of instruments. Confirmatory factor analysis (CFA) is one structural equation modeling procedure designed to assess construct validity of assessments that has broad applicability for counselors interested in instrument…

Diagnostic tools can help schools more consistently and fairly match instructional resources to the needs of their students. To ensure the best educational outcome for each child, diagnostic decision-making systems seek to balance time, clarity, and accuracy. However, recent research notes that many educational decisions tend to be made using…

Mixture factor analysis is examined as a means of flexibly estimating nonnormally distributed continuous latent factors in the presence of both continuous and dichotomous observed variables. A simulation study compares mixture factor analysis with normal maximum likelihood (ML) latent factor modeling. Different results emerge for continuous versus…

Power computations for one-level experimental designs that assume simple random samples are greatly facilitated by power tables such as those presented in Cohen's book about statistical power analysis. However, in education and the social sciences experimental designs have naturally nested structures and multilevel models are needed to compute the…

Many out-of-school time programs want to learn more about how the children and youth they serve are faring. Outcome evaluations allow programs to do just that. This brief provides a basic review of outcome evaluations, discusses why they are important and when they are useful, and presents guidelines, strategies, and techniques for their use in…

Supports a two-step approach to the estimation and discussion of effect sizes, making a distinction between single-study decision-oriented research and multiple-study synthesis. Introduces and illustrates the concept of "conclusion coherence." (Author/SLD)

This paper attempts to lay out some of the factors that need to be considered when a philanthropy decides to put a greater emphasis on "outcomes." The factors are divided into three broad categories: technical, substantive, and strategic. Technical factors are those dealing with how to measure outcomes. It must be recognized that…

This chapter provides an overview of sampling methods that are appropriate for conducting online surveys. The authors review some of the basic concepts relevant to online survey sampling, present some probability and nonprobability techniques for selecting a sample, and briefly discuss sample size determination and nonresponse bias. Although some…

This paper illustrates the use of the McNemar Test, using a hypothetical problem. The McNemar Test is a nonparametric statistical test that is a type of chi square test using dependent, rather than independent, samples to assess before-after designs in which each subject is used as his or her own control. Results of the McNemar test make it…

A multistakeholder evaluation procedure is presented to address the many challenges in evaluating the performance of condominial sewer projects in Brazil. Condominial sewerage is a promising appropriate technology that is coproduced by users and public agencies, but little is known about project performance. This article shows that…

This article considers various kinds of probability and non-probability samples in both experimental and survey studies. Throughout, how a sample is chosen is stressed. Size alone is not the determining consideration in sample selection. Good samples do not occur by accident; they are the result of a careful design. (Author/JAZ)

As item response theory (IRT) becomes popular in educational and psychological testing, there is a need of reporting IRT-based effect size measures. In this study, we show how the standardized mean difference can be generalized into such a measure. A disattenuation procedure based on the IRT test reliability is proposed to correct the attenuation…

Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) have contributed to test development and validation in counseling psychology, but additional applications have not been fully realized. The author presents an overview of the goals, terminology, and procedures of factor analysis; reviews best practices for extracting,…