The type I error rate in stepwise regression analysis deserves serious consideration by researchers. The problem-wide error rate is the probability of selecting any variable when all variables have population regression weights of zero. Appropriate significance tests are presented and a Monte Carlo experiment is described. (Author/CTM)

Disagreements have arisen about the robustness of the t test in normal populations with unequal variances. Employing liberal but objective standards for assessing robustness, it is shown that the t test is not always robust to the assumption of equal population variances even when sample sizes are equal. (Author/JKS)

Power analysis is in essence a technique for estimating the probability of obtaining a specific minimum observed effect size. Power analysis techniques are applied to research planning problems in test reliability studies. A table for use in research planning and hypothesis testing is presented. (Author)

Hollingsworth recently showed a posttest contrast for analysis of variance situations that, for equal sample sizes, had several favorable qualities. However, for unequal sample sizes, the contrast fails to achieve status as a maximized contrast; thus, separate testing of the contrast is required. (Author/GSK)

The author discusses the importance of statistical significance to researchers and suggests that researchers should consider an additional statistic, the magnitude of effect index. (MK)

A problem in analysis of variance is that after rejection of the overall hypothesis, no contrasts of interest are found to be significant. A procedure for determining the contrast of significance is outlined, and the relationship between the "most significant" contrast and the overall test is shown. (Author/JKS)

Details are given for the use of the mixed effects multivariate analysis of variance table provided by the BMD12V computer program to compute raw generalized variances and hence the U and F statistics for the mixed effects model. (Author/JKS)

A simple rationale for Scheffe's Method and Gabriel's Simultaneous Test Procedure is presented. Examples of both methods are provided. (Author)

An error is described that may occur in a posteriori testing, particularly when the original analysis of variance produces an F ratio that is just barely significant and the computer printout of the analysis does not provide the means that were used in the program. (Author/JKS)

This paper presents the generalized symmetric means approach to the estimation of population covariances, complete with derivations and examples. Particular attention is paid to the problem of missing data, which is handled very naturally in the incidence sampling framework. (CTM)

Practical significance is concerned with whether a research result is useful in the real world. The use of procedures to supplement the null hypothesis significance test in four journals of the American Psychological Association is examined, and an approach to assessing practical significance is presented. (SLD)

Describes a study that examined the editorial goals of three editors of "Elementary School Journal" and the citation patterns of the journal under each editor. Variables examined were number of citations received, number of citations given, immediacy index, and impact factor. It is concluded that editorial policy may have an impact on citation…

J. P. Shaffer has presented two tests to improve the power of multiple comparison procedures. This article described an algorithm to carry out the tests. The logic of the algorithm and an application to a data set are given. (SLD)

A generalized measure of association and an associated test of significance are presented for nominal independent variables in which any number or combination of interval, ordinal, or nominal dependent variables can be analyzed. A permutation test of significance is provided for the new measure. (SLD)

Responds to Biskin's comments (this issue) on the significance test controversy. Highlights areas of agreement (importance of replication evidence, importance of effect sizes) and disagreement (influence of sample size, evaluation of populations vs. samples, significance of Carver's article). Includes further recommendations for reporting research…