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…

Analyzed 150 articles from the "Journal of Applied Psychology" (JAP) from 1940 to 1999 to determine statistical reporting practices related to null hypothesis significance testing, American Psychological Association guidelines, and reform recommendations. Findings show little evidence that decades of cogent criticisms by reformers have…

Shows, through a Monte Carlo experiment, that statistical significance testing and effect size are related and complementary but do not substitute for each other, noting that good research requires consideration of both. Results of the experiment indicate that there is considerable variability in the sample effect size measure, and the extent of…

Presents exercises in which students can explore Type I and Type II errors using sporangia diameter measurements as a means of differentiating between two species. Examines the influence of sample size and significance level on the outcome of the analysis. (SAH)

Reviews practices regarding tests of statistical significance and policies of the American Educational Research Association (AERA). Decades of misuse of statistical significance testing are described, and revised editorial policies to improve practice are highlighted. Correct interpretation of statistical tests, interpretation of effect sizes, and…

A sample of 113 American Vocational Education Research Association members (93% with doctorates, 67% with more than 15 years of research experience) disagreed that statistical significance tests should be banned; were less likely to realize that stepwise methods do not identify the best predictor set; and recognized that studies with…

In this paper, I trace the development of statistical significance testing standards in sociology by analyzing data from articles published in two prestigious sociology journals between 1935 and 2000. I focus on the role of two key elements in the diffusion literature, contagion and rationality, as well as the role of institutional factors. I find…

Health care and educational trials face similar methodological challenges. Methodological reviews of health care trials have shown that a significant proportion have methodological flaws. Whether or not educational trials have a similar proportion of poor-quality trials is unknown. The authors undertook a methodological comparison between health…