Explains the use of the construct representation and inference functions of indicators used in construct measurements of self-concept. Illustrates validity and reliability issues with data from 2,114 12th-grade vocational-technical students. (SK)

Two longitudinal studies examined patterns of reading disability in children. Results indicated that remission of reading disability was relatively common with up to 37% of reading-disabled children showing remission within a 2-year period. Results suggest that the presence of measurement errors may lead to misleading impression of the rate of…

A microcomputer program that computes statistical power for analyses performed by multiple regression/correlation is described. The program features a spreadsheet-like interface, outputting the effect size and value of power corresponding to the input parameters, including predictor variables, sample size, alpha, and error type. (TJH)

Described is the derivation of the relationship between the pH measurement error and the resulting percentage error in hydrogen ion concentration including the use of variable activity coefficients. The relative influence of the ionic strength of the solution on the percentage error is shown. (CW)

Functional and structural relationship alternatives to the standard "F"-test for analysis of covariance (ANCOVA) are discussed for cases when the covariate is measured with error. An approximate statistical test based on the functional relationship approach is preferred on the basis of Monte Carlo simulation results. (SLD)

It has been proposed that the Objective Measure of Ego Identity Status and its scoring criteria should be adjusted to utilize a half standard deviation cutoff. Evidence is provided to support the claim that less stringent criteria will lead to higher numbers classified while arriving at the same research results. This proposal is considered and,…

A comparison is made of the power and actual alpha levels of three tests of homogeneity for independent product-moment correlation coefficients using Monte Carlo methods while selectively studying sample size and varying the number of correlation reliabilities. How robust these are in applied work is discussed. (SLD)

Presents an exercise that gives students a real feeling for experimental errors and demonstrates the importance of frequent repetition and averaging. (JRH)

Application of the bootstrap method to complex psychological analysis is illustrated using a simulation experiment with two populations with small and large samples. The method provides variance estimates, allows testing of nested competing models, and gives a preliminary idea about parameter variability. (SLD)

W. M. K. Trochim and others defend the record of the regression-discontinuity (RD) design and blur the statistical tests for treatment effect. Their Monte Carlo results show the problematic nature of RD and its potential bias. New testing strategies and restrictions for the application of RD are proposed. (SLD)

Multilevel models used to assess and compare school effectiveness, particularly their application to multivariate data, are critiqued. Problems associated with standard errors of measurement and the various components of "school effect" are highlighted in terms of how they could affect incautious application of the models. (TJH)

Four approaches to estimating interrater reliability in early childhood special education research are illustrated and compared: correlation, comparison of means, percentage of agreement, and generalizability theory techniques. Generalizability theory techniques are proposed as a method for estimating the amount of variance attributable to…

Pseudo-Maximum Likelihood (p-ML) and Asymptotically Distribution Free (ADF) estimation methods for estimating dynamic factor model parameters within a covariance structure framework were compared through a Monte Carlo simulation. Both methods appear to give consistent model parameter estimates, but only ADF gives standard errors and chi-square…

Presents a general discussion of the conceptual and operational limitations found within the existing efforts to assess constructs central to the study of parents. The discussion is followed by a review and critique of measures designed to assess concepts central to research on parents. Includes recommendations to improve the quality of measures.…

Empirical studies demonstrated Type-I error (TIE) inflation (especially for highly discriminating easy items) of the Mantel-Haenszel chi-square test for differential item functioning (DIF), when data conformed to item response theory (IRT) models more complex than Rasch, and when IRT proficiency distributions differed only in means. However, no…