Derived an approximate test and confidence interval for coefficient alpha and used the approximate test and confidence interval to derive closed-form sample size formulas that can be used to determine the sample size needed to test coefficient alpha with desired power or to test coefficient alpha with desired precision. (SLD)

Explores the asymptotic theory of a method of nonparametric item characteristic curve estimation based on kernel smoothing with the theory of obtaining the proper linear ordering of examinees with respect to their true latent abilities. Results support the usefulness of estimates of the type produced by the TESTGRAF program. (SLD)

The benefits of item response theory (IRT) will only accrue to a testing program to the extent that model assumptions are met. Obtaining accurate item parameter estimates is a critical first step. However, the sample sizes required for stable parameter estimation are often difficult to obtain in practice, particularly for the more complex models.…

The jackknife statistic is discussed as a viable invariance procedure. Data from a study of leadership illustrates the use of the jackknife in determining the stability of canonical function coefficients following canonical correlation analysis. The jackknife procedure entails arbitrarily omitting one observation or a subset of observations at a…

Investigated the assumption that determining an adequate sample size in structural equation modeling can be aided by considering the number of parameters to be estimated. Findings from maximum likelihood confirmatory factor analysis support previous research on the effect of sample size, measured variable reliability, and the number of measured…

Derived general formulas to determine the sample size requirements for hypothesis testing with desired power and interval estimation with desired precision. Illustrated the approach with the example of a screening test for adolescent attention deficit disorder. (SLD)

Monte Carlo methods were used to study the accuracy and utility of estimators of overall error and error due to approximation in structural equation modeling. Effects of sample size, indicator reliabilities, and degree of misspecification were examined. The rescaled noncentrality parameter also was examined. Choosing among competing models is…

Simulations were used to compare the moderator variable detection capabilities of moderated multiple regression (MMR) and errors-in-variables regression (EIVR). Findings show that EIVR estimates are superior for large samples, but that MMR is better when reliabilities or sample sizes are low. (SLD)

Monte Carlo methods are used to evaluate marginal maximum likelihood estimation of item parameters and maximum likelihood estimates of theta in the two-parameter logistic model for varying test lengths, sample sizes, and assumed theta distributions. Results with 100 datasets demonstrate the methods' general precision and stability. Exceptions are…

The stability of bias estimates from J. Schueneman's chi-square method, the transformed Delta method, Rasch's one-parameter residual analysis, and the Mantel-Haenszel procedure, were compared across small and large samples for a data set of 30,000 cases. Bias values for 30 samples were estimated for each method, and means and variances of item…

The degree to which reliability affects the power of analysis of variance (ANOVA) tests involving one factor with two and three samples was quantified and tabulated by taking into account sample size, level of significance, and true score effect size. Results confirm a substantial effect on power. (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)

Researchers have been limited in their ability to examine multiple constructs simultaneously due to the constraints imposed by traditional statistical methods. The most notable limitations include the need for a relatively large sample size while restricting the variables to a relatively small number. The application of a newly discovered…

In an investigation of item bias, the stability of Mantel-Haenszel (MH) estimates across different samples of test takers and different sample sizes and the robustness of the MH procedure with respect to item context effects were investigated. Data from the Second International Mathematics Study (1985) were analyzed. The data consisted of…

The National Household Education Survey (NHES) was conducted for the first time in 1991 as a way to collect data on the early childhood education experiences of young children and participation in adult education. Because the NHES methodology is relatively new, field tests were necessary. A large field test of approximately 15,000 households was…