Sampling theory for the intraclass reliability coefficient, a Spearman-Brown extrapolation of alpha to a single measurement for each examinee, is less recognized and less cited than that of coefficient alpha. Techniques for constructing confidence intervals and testing hypotheses for the intraclass coefficient are presented. (SLD)

Examined Type I error rates and power for four tests for treatment control studies in which a larger treatment mean may be accompanied by a larger treatment variance and examined these aspects of the independent samples "t" test and the Welch test. Evaluated each test and suggested conditions for the use of each approach. (SLD)

This study utilized a rating scale and random sampling of Connecticut school speech-language pathologists about their preprofessional education and current knowledge of autism spectrum disorders (ASD). The participants had a minimal amount of preprofessional academic or clinical preparation in ASD, and no differences were found in how…

All differential item functioning (DIF) methods require at least a moderate sample size for effective DIF detection. Samples that are less than 200 pose a challenge for DIF analysis. Smoothing can improve upon the estimation of the population distribution by preserving major features of an observed frequency distribution while eliminating the…

This article examines theoretical and empirical issues related to the statistical power of impact estimates for experimental evaluations of education programs. The author considers designs where random assignment is conducted at the school, classroom, or student level, and employs a unified analytic framework using statistical methods from the…

This article highlights the problem of omitted variable bias in research on the causal effect of financial aid on college-going. I first describe the problem of self-selection and the resulting bias from omitted variables. I then assess and explore the strengths and weaknesses of random assignment, multivariate regression, proxy variables, fixed…

As a result of the federal No Child Left Behind Act (NCLB) of 2002, the field of education has seen a heavy emphasis on the use of "scientifically based research" for designing and testing the effectiveness of new and existing educational programs. According to NCLB, when addressing basic cause and effect questions scientifically based…

Background: A literature search found five empirical studies of psychological treatment for adults with ADHD, out of 1,419 articles on ADHD in adults. Practice guidelines to date all recommend multimodal intervention, given that a significant number of patients cannot tolerate, do not respond to, or fail to reach optimal outcomes with medication…

This article familiarizes readers with how to analyze personnel selection decisions in employment discrimination litigation. First, the authors outline some of the basic legal principles that serve as the basis for analyses related to claims of discriminatory employment practices. Second, they describe how to conduct a scientific investigation of…

The National Household Education Surveys Program (NHES) is a random digit dialing (RDD) survey program developed by the National Center for Education Statistics (NCES) in the Institute of Education Sciences, U.S. Department of Education. The surveys are designed to help NCES collect data directly from households about important education topics.…

This report presents the findings from the second National Assessment Program--Civics and Citizenship, conducted under the auspices of the national council of education ministers, the Ministerial Council on Education, Employment, Training and Youth Affairs (MCEETYA). The National Assessment Program--Civics and Citizenship measures Year 6 and Year…

Measurement error is a common theme in classical measurement models used in testing and assessment. In classical measurement models, the definition of measurement error and the subsequent reliability coefficients differ on the basis of the test administration design. Internal consistency reliability specifies error due primarily to poor item…

The technique of distance sampling is widely used to monitor biological populations. This paper documents an in-class activity to introduce students to the concepts and the mechanics of distance sampling in a simple situation that is relevant to their own experiences. Preparation details are described. Variations and extensions to the activity are…

Reporting methods used in large-scale assessments such as the National Assessment of Educational Progress (NAEP) rely on latent regression models. To fit the latent regression model using the maximum likelihood estimation technique, multivariate integrals must be evaluated. In the computer program MGROUP used by the Educational Testing Service for…

This article demonstrates the use of mixed-effects logistic regression (MLR) for conducting sequential analyses of binary observational data. MLR is a special case of the mixed-effects logit modeling framework, which may be applied to multicategorical observational data. The MLR approach is motivated in part by G. A. Dagne, G. W. Howe, C. H.…