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…

Effect sizes are critical to result interpretation and synthesis across studies. Although statistical significance testing has historically dominated the determination of result importance, modern views emphasize the role of effect sizes and confidence intervals. This article accessibly discusses how to calculate and interpret the effect sizes…

The purpose of this study was to examine the effect of a constant time delay (CTD) procedure on teaching a recreational bowling skill to a 39-year-old male with severe mental retardation. The CTD procedure used 5 seconds as delay interval, task direction as target stimulus, physical assistance as controlling prompt, and oral praise as reinforcer.…

This article describes an example which is useful when teaching hypothesis testing in order to highlight the interrelationships that exist among the level of significance, the sample size and the statistical power of a test. The example also allows students to see how what they learn in the classroom directly affects the content of some of the…

The issue of live bibliographic instruction (BI) versus electronic BI is a matter many libraries are facing as more technology becomes available to afford such an option. At the University of Oklahoma Government Documents Collection, a study was administered in March 2001 to determine the relative advantages between these two teaching techniques.…

Empirical analysis requires researchers to choose which variables to use as controls in their models. Theory should dictate this choice, yet often in social science there are several theories that may suggest the inclusion or exclusion of certain variables as controls. The result of this is that researchers may use different variables in their…