A five by five covariance matrix representing longitudinal measurements at five occasions is used to illustrate that markedly different types of learning curves may generate indistinguishable covariance structures. An excellent fit of a simplex structure can be misleading. Common uses of covariance structure models for growth studies are…

Drawing on recently developed methodology for structural equation modeling with categorical data, this article proposes a new approach for investigating the behavior of dichotomously scored test items in relation to other relevant (observed) variables. A linear structural model relates the latent ability variable to a set of observed scores.…

An empirical study of statistical overkill investigated the generalizability of multiple regression equations as a function of the subject/variable ratio. Data from various-sized groups of rehabilitation clients were used to develop the equations. Findings showed that equations developed on samples with less than a 10 to 1 ratio failed to…

This study assesses 78 emotionally disturbed children on the Wechsler Intelligence Scale for Children (WISC) and the revised edition of the Illinois Test of Psycholinguistic Abilities (ITPA) to demonstrate the relationship between the two tests and determine which revised ITPA subtest scores best predict the children's WISC Full Scale, Verbal and…

Research supported by a grant from the National Research Council of Canada. (RS)

This article aims to (1) propose a new approach to establishing English-as-a-second-dialect programs in schools isolated from professional English-second-language personnel, (2) to report on the procedures applied at one particular high school, and (3) to discuss linguistic features typical of the Negro students in this school. (Author/FB)

Presents several multivariate analyses of variance (MANOVA) test procedures. Discusses guidelines for choosing an overall MANOVA test statistic and post hoc tests that determine the dependent variable or variables responsible for any significant effects. Concludes that guidelines based on recent comparisons of the various test statistics be used.…

The "factor" analyses published by Schultz, Kaye, and Hoyer (1980) confused component and factor analysis and led to unwarranted conclusions. The principal factors method yields two factors which support the a priori expectation of a difference between intelligence tasks and spontaneous flexibility tasks. (Author/RD)

Proposes a means for determining the similarity between search request formulations in online information retrieval systems, and discusses the use of similarity measures for clustering search formulations and document files in such systems. Experimental results using the proposed methods are presented in three tables. A reference list is provided.…

Appropriate methods are described for research workers in sociology to use as they perform causal analyses of data from surveys. Particular emphasis is placed on the causal analysis of qualitative variables. (Author/DB)

Computer simulations indicate that the correlation between baseline and change, by itself, does not invalidate the use of gain scores to measure change, but when the negative correlation is accompanied by decrease in variance from pretest to posttest, covariance is a superior measure of change. (SLD)

Alternative tests are presented for the between-by-within interaction null hypothesis and for two within-subjects main effects null hypothesis in a split plot design. Estimated Type I error rates for the interaction tests and for several tests of the second null hypothesis are reported. (SLD)

A data set (4,398 drug offenders from Florida) is used to estimate impacts of probation and imprisonment on recidivism and to explore the impact of biases related to selection and interruption of the duration of probation. Correcting for these biases leaves no evidence that probation impacts on duration of recidivism. (SLD)