Most researchers using analysis of variance (ANOVA) use a fixed-effects model. However, a random- or mixed-effects model may be a more appropriate fit for many research designs. One benefit of the random- and mixed-effects models is that they yield more generalizable results. This paper focuses on the similarities and differences between the…

Experimenters sometimes wish to estimate for a particular dependent variable the proportion of total group variance that is associated with mean differences among fixed treatments or subject classifications. Hays (1981) represents this proportion by the parameter omega squared. A point estimate may be easily computed as a function of the number of…

The value of variance is emphasized, and the element of design, frequently not adequately understood, is clarified to underscore the importance of variance to the researcher. Two analytic methods, analysis of variance (ANOVA) and multiple regression, are discussed in terms of how each uses/applies variance. Advantages and major difficulties with…

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…

This paper examined the rank transformation approach to analysis of variance as a solution to the Behrens-Fisher problem. Using simulation methodology four parameters were manipulated for the two group design: (1) ratio of population variances; (2) distribution form; (3) sample size and (4) population mean difference. The results indicated that…

In behavior research using cognitive and affective measures, there is often incongruity between the statistical analysis employed and the intended inference. This paper argues that incorporating items as levels of a random facet via generalizability theory allows the statistical examination of the inferential question in the desired universe of…

A statistical method has been developed for nested incomplete samples in a longitudinal study in which part of the sample has dropped out in such a way that the data have a nested pattern. A procedure which performed well in a Monte Carlo experiment was extended to a two-factor incomplete design with repeated measures on one factor. Methods…

In order to examine the possible effects of violation of assumptions using parametric procedures, this study is an exploratory investigation into the use of parametric versus nonparametric procedures using a multiple case study design. The case study investigation guidelines outlined by Yin served as the methodology. The following univariate…

Political communication researchers recently have emphasized conditional relationships as crucial to specifying and understanding the effects of the mass media. In many cases, however, researchers will not predict which variables will modify the form or existence of media effects. They therefore will not include measures of the conditional…

This paper provides an understanding of the conceptual and operational relationships between evaluation, content analysis, and microcomputers so that evaluation practitioners can better address applied content analysis problems used in their work. The first section presents a general model for conducting an evaluation effort that focuses on…

Hypothetical data sets are used to demonstrate how canonical correlation methods subsume other commonly utilized parametric methods. Analysis of variance, analysis of covariance, multiple analysis of variance, and multiple analysis of covariance are heavily used by educational researchers. It is concluded that researchers would do well to consider…

The central purpose of the present study was to evaluate several statistical techniques (analysis of variance (ANOVA) on raw gains, standardized ANOVA, standard analysis of covariance (ANCOVA), and z-score ANOVA) under various quasi-experimental conditions (three levels of reliability, three levels of sample size, three levels of gain, and the…

Review of a research study designed to determine the relationship between participation in supervisory training and managerial performance focuses on the importance of adequate evaluation. Dependent and independent variables used are described, statistical analyses are explained, and implications for future research design are presented. (LRW)

This paper reports the results of a Monte Carlo investigation of Type I errors in the single group repeated measures design where multiple measures are collected from each observational unit at each measurement occasion. The Type I error of three multivariate tests were examined. These were the doubly multivariate F test, the multivariate mixed…

Investigated the extent to which three personological variables (age, level of education, and attitude towards television) affect the amount learned from a documentary by adults over 50 years of age. The results indicated that education was the most reliable and important predictor of retention: as education increased, so did retention. (Author/RP)