This paper briefly describes unplanned and planned methods of evaluating differences between means and explains orthogonal versus nonorthogonal contrasts to help the researcher understand a framework of planned comparisons. A small heuristic data set is generated to illustrate the superiority of planned comparisons over omnibus analysis of…

Some interpretations of relative variable importance in the contexts of multivariate analysis of variance (MANOVA) and discriminant analysis (DA) are presented. Some indices potentially useful for the interpretations are presented, and the assessment of variable importance is illustrated using real data sets. Both descriptive discriminant analysis…

Compares creativity measures for three groups of students: teacher-nominated, peer-nominated, and control. Teachers were more effective in recognizing creativity than peers. Peer nominees were less alienated than the other groups. (DR)

By employing a concomitant variable, block designs and analysis of covariance (ANCOVA) can be used to improve the power of traditional analysis of variance (ANOVA) by reducing error. If subjects are randomly assigned to treatments without considering the concomitant variable, an experiment uses a post-hoc approach. Otherwise, an a priori approach…

A multivariate post hoc procedure (the Roy-Bose procedure) which allows for the construction of an infinite number of confidence intervals or probability statements concerning the p variables, all of which hold at a 100(1-a) percent level of confidence, is demonstrated and compared to other procedures. (JD)

The advantages and disadvantages of three analytic methods used to analyze experimental data in educational research are discussed. The same hypothetical data set is used with all methods for a direct comparison. The Analysis of Variance (ANOVA) method and its several analogs are collectively labeled OVA methods and are evaluated. Regression…

The author illustrates the shortcomings of pooling data from replication and original studies. If combining data is deemed necessary, procedures should be rigorous to identify statistically widen study differences. When sources of variation are easily identifiable, an analysis of variance may be superior to a series of separate t-tests.…

The literature is reviewed regarding the difference between planned contrasts, OVA and unplanned contrasts. The relationship between statistical power of a test method and Type I, Type II error rates is first explored to provide a framework for the discussion. The concepts and formulation of contrast, orthogonal and non-orthogonal contrasts are…

The assumptions and consequences of applying conventional and newer statistical methods to meta-analytic data sets are reviewed. The application of the two approaches to a meta-analytic data set described by L. V. Hedges (1984) illustrates the differences. Hedges analyzed six studies of the effects of open education on student cooperation. The…

It is argued that there is a benefit to applying techniques of exploratory data analysis (EDA) to program evaluation. The evaluation of a rehabilitation program for people with rheumatoid arthritis (20 subjects and 21 comparisons) through EDA supports the argument, indicating outcomes more precisely than conventional analysis of variance. (SLD)

The use of the Analytic Hierarchy Process (AHP) in assisting researchers to analyze decisions is discussed. The AHP is compared with other decision-analysis techniques, including multiattribute utility measurement, conjoint analysis, and general linear models. Insights that AHP can provide are illustrated with data gathered in an auditing context.…

There are advantages to using a priori or planned comparisons rather than omnibus multivariate analysis of variance (MANOVA) tests followed by post hoc or a posteriori testing. A small heuristic data set is used to illustrate these advantages. An omnibus MANOVA test was performed on the data followed by a post hoc test (discriminant analysis). A…