The regression-discontinuity design involving a treatment interaction effect (TIE), pretest-posttest functional form specification, and choice of point-of-estimation of the TIE are examined. Formulas for controlling the magnitude of TIE in simulations can be used for simulating the randomized experimental case where estimation is not at the…

This paper discusses standard error of measurement (SEM), the amount of variation or spread in the measurement errors for a test, and gives information needed to interpret test scores using SEMs. SEMs at various score levels should be used in calculating score bands rather than a single SEM value. (SLD)

Simulated data typical of those from meta analyses are used to evaluate the reliability, Type I and Type II errors, bias, and standard error of the meta-analytic procedures of Schmidt and Hunter (1977). Concerns about power, reliability, and Type I errors are presented. (SLD)

Evidence is presented on the generalizability and convergent validity of performance assessments using data from six studies of student achievement that sampled a wide range of measurement facets and methods. Results at individual and school levels indicate that task-sampling variability is the major source of measurement error. (SLD)

Examined the generalizability of written-response scores on the English 30 diploma examination administered to Alberta 12th-grade students. Student scores differed as a function of rater, but this variance component was small across two tasks and two administrations; score generalizability was high using a two-rater system; and scale variability…

A meta-analysis for six weight-loss studies comparing the efficacy of cognitive-behavior therapy (CBT) alone to CBT plus hypnotherapy. Notes that "the addition of hypnosis substantially enhanced treatment outcome." Concludes that the addition of hypnosis to CBT for weight loss results in, at most, a small enhancement of treatment…

D.V. Cicchetti, A.S. Kaufman, and S.S. Sparrow (this issue) examine various technical issues related to six studies of perinatal PCB exposure and neurodevelopment and one study of adult PCB exposure and motor function. They raise questions about possible imperfections of the studies, but many of their assertions are unsupported or frankly…

Cox (1972) proposed a discrete-time survival model that is somewhat analogous to the proportional hazards model for continuous time. Efron (1988) showed that this model can be estimated using ordinary logistic regression software, and Singer and Willett (1993) provided a detailed illustration of a particularly flexible form of the model that…

The diagnosis of developmental dyslexia (DD) is reliant on a discrepancy between intellectual functioning and reading achievement. Discrepancy-based formulae have frequently been employed to establish the significance of the difference between "intelligence" and "actual" reading achievement. These formulae, however, often fail to take into…

Generalizability (G) theory was used with a sample of 37 third-grade students to assess the variability in words correct per minute (WCPM) scores caused by student skill and passage variability. Reliability-like coefficients and the SEM based on a specific number of assessments using different combinations of passages demonstrated how manipulating…

A hierarchical latent regression model is suggested to estimate nested and nonnested relationships in complex samples such as found in the National Assessment of Educational Progress (NAEP). The proposed model aims at improving both parameters and variance estimates via a two-level hierarchical linear model. This model falls naturally within the…

The development of the DETECT procedure marked an important advancement in nonparametric dimensionality analysis. DETECT is the first nonparametric technique to estimate the number of dimensions in a data set, estimate an effect size for multidimensionality, and identify which dimension is predominantly measured by each item. The efficacy of…

In this article, we formulate a nonlinear structural equation model (SEM) that can accommodate covariates in the measurement equation and nonlinear terms of covariates and exogenous latent variables in the structural equation. The covariates can come from continuous or discrete distributions. A Bayesian approach is developed to analyze the…

Value-added models in education research allow researchers to explore how a wide variety of policies and measured school inputs affect the academic performance of students. Researchers typically quantify the impacts of such interventions in terms of "effect sizes", i.e., the estimated effect of a one standard deviation change in the…

An attempt was made to evaluate the standard error of equating (at the mean of the scores) in an ongoing testing program. The interest in estimating the empirical standard error of equating is occasioned by some discomfort with the error normally reported for test scores. Data used for this evaluation came from the Admissions Testing Program of…