A weighted harmonic means analysis is presented that incorporates all of the available data, preserves the planned proportionality of the design, and avoids the problems associated with the replacement of missing data with sample estimates. (Author/BW)

An experimental sampling procedure for communities on which coal had been surface-mined yielded missing cells and caused the number of degrees of freedom to be N instead of the usual N minus one. The apparent discrepancy is explained, and a solution to the problem is presented. (Author/JKS)

The authors argue that a parameterization in terms of cell means is a useful conceptual device for resolving problems inherent in the nonorthogonal analysis of variance. They demonstrate their argument by considering two widely-used methods for testing main effects. (Author/BW)

It is argued here that the choice of the appropriate method for calculating least squares analysis of variance with unequal sample sizes depends upon the question the experimenter wants to answer about the data. The different questions reflect different null hypotheses. An example is presented using two alternative methods. (Author/BW)

The problem of determining which of several populations has the largest mean is considered. The procedure described by Dudewicz and Dalal is extended to the case of unequal sample sizes. (JKS)

Analysis of 19 studies using omnibus analysis of variance (ANOVA) F-tests resulted in reasons for replacing ANOVA with focused hypothesis testing, which is easy to compile and understand; is flexible; enables trend analysis, determination of confidence intervals, adjustments for violated assumptions, and control of Type 1 errors; makes effect size…

A correction of the standard F-ratio for unreliability of the dependent measure has recently been proposed by Winne; the rationale is analogous to that of correcting a correlation for attenuation. However, there are two problems associated with Winne's correction of which potential users should be aware. First, the corrected statistic, F*, has…

This paper is concerned with testing hypotheses about main effects, simple effects, and interaction effects by means of analysis of variance. It presents alternative strategies for analyzing data sets for which a factorial model with two completely crossed, fixed factors is appropriate. (CTM)

Several procedures proposed in the literature for the analysis of growth curves are reviewed. Particular attention is given to the current issues in this area to guide practitioners in the selection of the most appropriate methodology. (Author)

The adequacy of traditional effect size measures for research synthesis is challenged. Analogues to analysis of variance and multiple regression analysis for effect sizes are presented. The importance of tests for the consistency of effect sizes in interpreting results, and problems in obtaining well-specified models for meta-analysis are…

The basic notion of variability is generalized from a univariate context to a multivariate context using two matrix functions, a determinant, and a trace, yielding a number of alternative multivariate indices of shared variation. Some problems in the interpretation of tests of multivariate hypotheses are reviewed. (Author/BW)

The recommendation to use group means when there may be nonindependence among observational units is unduly restrictive. When random factors are properly identified and included in the analysis, the results are identical in balanced analysis of variance designs, irrespective of whether group means or individual observations are employed.…

Presents reasons therapist should be included as random design factor in nested analysis of (co)variance (AN[C]OVA) design used in psychotherapy research. Reviews studies which indicate majority of investigators ignore issue of effects from incorrect specification of ANOVA design. Presents reanalysis of data from 10 psychotherapy outcome studies…

This interim report is concerned with the analysis of educational experiments and quasiexperiments where alternative teaching methods are applied to intact classes or where alternative programs are set up in samples of schools or communities. Generally, such studies have used the class, the school, or the community as the unit of sampling with the…

The author examined the prevalence of multiple operational definitions of outcome constructs and an estimate of the incidence of Type I error rates when univariate procedures were applied to multiple variables in educational psychology. Multiple operational definitions of constructs were advocated and wider use of multivariate analysis was…