A statistical model for relating latent variables from manifest variables, called a linear structural equation model, is presented. The approach is illustrated by a test theory model and longitudianl study of intelligence. (Author/JKS)

For Y. Yao's and G. S. James' tests, Type I error rates were estimated for various combinations of the number of variables, sample-size and sample-size-to-variables ratios, and heteroscedasticity. These tests are alternatives to Hotelling's T(sup 2) and are intended for use when variance-covariance matrices are unequal for two independent samples.…

Formulas are provided for estimating statistical power of a test of significance for the difference among means under a variety of conditions. A table for quick power estimates that require no computation for comparing two means in analysis of variance and analysis of covariance is included. (TJH)

Parametric analysis of covariance was compared to analysis of covariance with data transformed using ranks. Using a computer simulation approach the two strategies were compared in terms of the proportion of Type I errors made and statistical power when the conditional distribution of errors were: (1) normal and homoscedastic, (2) normal and…

Since measurement errors exist in panel surveys, LISREL (a procedure for controlling measurement error by the analysis of covariance structures) was used in this investigation to determine the stability of the social-psychological concept of locus of control expectancy change with the aquisition of post secondary education. The National…

Design, analysis, and reporting considerations for the application of analysis of covariance (ANCOVA) techniques in educational settings are described. Numerous examples are drawn from the national follow through evaluation, and suggestions for improving reports using ANCOVA-type techniques are presented. (Author/BW)

Derivation of asymptotic variance-covariance matrices for item and personal parameters in item response models is demonstrated for one- and two-parameter models using maximum likelihood estimation. The results can be used in incomplete designs and in estimation of the accuracy of various designs beforehand. (TJH)

The nature and appropriate application of the technique of multivariate analysis are discussed. More specifically, the intent of the paper is to demystify and explain the use of multivariate analysis as well as provide guidelines for selection of the most effective statistics for use in specific situations. For the purpose of this paper, the term…

Six models for evaluating change are examined via a Monte Carlo study. All six models show a lack of power. A modified analysis of variance procedure is suggested as an alternative. (JKS)

This Monte Carlo study examined the validity of the chi-square test for model evaluation in different instances of misspecification and sample size. The usefulness of the chi-square difference statistic to compare competing structures and improvement in fit is also addressed. (Author/BS)

The results of six major projects are discussed including a comprehensive mathematical and statistical analysis of the problems caused by errors of measurement in linear models for assessing change. In a general matrix representation of the problem, several new analytic results are proved concerning the parameters which affect bias in…

Attitude measures frequently produce distributions of item scores that attenuate interitem correlations and thus also distort findings regarding the factor structure underlying the items. An actual data set involving 260 adult subjects' responses to 55 items on the Love Relationships Scale is employed to illustrate empirical methods for…

A teaching aid appropriate for a beginning course on experimental design is presented. The aid is a numerical example which illustrates some of the theoretical interrelations among three competing design analysis strategies for estimating treatment effects in random assignment designs. The analysis strategies considered are analysis of variance…

Covariance structure modelling is applied to the problem of estimating reliability and measurement error in survey data. To provide a basis for grouping certain question or variable types (data from questions), a simple typology based on the formal characteristics of the questions is outlined. From this classification, models for the different…

The RMC Research Corporation evaluation model C1--the special regression model (SRM)--was evaluated through a series of computer simulations and compared with an alternative model, the norm referenced model (NRM). Using local data and national norm data to determine reasonable values for sample size and pretest posttest correlation parameters, the…