The probabilities of attaining varying magnitudes of standardized effect sizes by chance and when protected by a 0.05 level statistical test were studied. Monte Carlo procedures were used to generate standardized effect sizes in a one-way analysis of variance situation with 2 through 5, 6, 8, and 10 groups with selected sample sizes from 5 to 500.…

Reviews a recent paper by Levy (1982) which concluded that a new format of the Peabody Picture Vocabulary Test was valid for autistic children. Claims the analysis was inappropriate and presents a statistical test to compare differences between independent mean differences. Includes a reply by Stine Levy. (Author/JAC)

Critiqued and reanalyzed a recent study of the validity of five Minnesota Multiphasic Personality Inventory (MMPI) alcoholism scales. The original study concluded that these scales were invalid in terms of classifying patients in regard to alcoholic status. Reanalysis provides evidence for the validity of four of the five scales. (Author/JAC)

Focuses on Binomial Effect Size Display (a concept helpful in interpreting size of an experimental effect). Suggests that both statistical significance and explained variance be reported in experimental research and that values for the latter concepts can be viewed with a more accurate perspective by using BESD. (Author/JN)

The assumption of equal treatment implementation is questioned. Through the reanalysis of data from a nutrition supplementation program evaluation, the power of the analysis of treatment effects is shown to increase when data on the level of treatment implementation is included. (Author/CM)

A reliability study is illustrated in which subjects are judged on a dichotomous trait by different sets of judges, possibly unequal in number. A kappa-like measure of reliability is proposed, its correspondence to an intraclass correlation coefficient is pointed out, and a test for its statistical significance is presented. (Author/CTM)

A process is described for multiple comparisons when covariates are involved in the analysis. The method can be accomplished with considerable ease whenever pairwise comparisons are involved. More complex contrasts require the use of full and restricted models of variance. (CTM)

Raw scores for the clinical scales of MMPI can be changed to T scores by linear transformation. If the underlying distributions of raw scores are not distributed normally, one cannot assume the traditional point of significance. Suggests that clinicians consider more conservative interpretation for some scales. (Author)

When reporting results, researchers must not change predetermined significance levels. Such attempts to make results more significant are statistically inaccurate, illogical, and unethical. American Psychological Association standards for reporting significance should be more explicit. (CP)

A procedure for approximating attained significance levels of exact conditional tests is proposed. The procedure utilizes a sampling from the null distribution of tables having the same marginal frequencies as the observed tables. (Author/JKS)

The negative bias of biserial correlations in the presence of guessing is demonstrated by Monte Carlo studies, and another estimator is described that is free of such bias. The usual biserial-correlation assumptions and assumptions about guessing are discussed. Brogden's coefficient of selective efficiency and the triserial correlation are…

A Monte Carlo technique was used to investigate the effect of the differences in covariate means among treatment groups on the significance level and the power of the F-test of the analysis of covariance. (Author/GDC)