A concise table is presented based on a general measure of magnitude of effect which allows direct determinations of statistical power over a practical range of values and alpha levels. The table also facilitates the setting of the research sample size needed to provide a given degree of power. (Author/CM)

Psychophysicists neglect to consider how error should be characterized in applications of the power law. Failures of the power law to agree with certain theoretical predictions are examined. A power law with lognormal product structure is proposed and approximately unbiased parameter estimates given for several common estimation situations.…

Two r coefficients of association are discussed. One of the coefficients can be applied to any nonparametric test statistic (NTS) in which a normal approximation equation is appropriate. The other coefficient is applicable to any NTS in which exact probabilities are known. (Author/RL)

Order analysis, a technique to isolate unidimensional hierarchies representing multidimensional structure of binary data, is reviewed. Several theoretical flaws inherent in the probalistic version are presented. Suggestions of possible directions for future research are offered. (Author)

The procedures yielding confidence intervals for maximized alpha coefficients of Joe and Woodward are reviewed. Confidence interval procedures of Whalen and Masson are next reviewed. Results are then presented of a Monte Carlo investigation of the procedures. (Author/CTM)

Sixteen tables are presented for critical values of the larger of two sample correlation coefficients from two independent samples, given the sample size and the value of the smaller correlation. These tables allow quick assessment of significance without requiring calculation of the test statistic. (SLD)

Minkowski distances are used to indicate similarity of two vectors in an N-dimensional space. How to compute the probability function, the expectation, and the variance for Minkowski distances and the special cases City-block distance and Euclidean distance. Critical values for tests of significance are presented in tables. (SLD)

Considers relationship between statistically and clinically significant change. Sees Jacobson and Truax's index of clinically significant change as neglecting possible confounding of improvement rate estimates by regression to the mean. Describes alternative method (Edwards-Nunnally method) that incorporates an adjustment that minimizes this…

Describes MINSIZE, an MS-DOS computer program that permits the user to determine the minimum sample size needed for the results of a given analysis to be statistically significant. Program applications for statistical significance tests are presented and illustrated. (SLD)

Illustrates and compares three alternative procedures to adjust significance levels for multiplicity: (1) the traditional Bonferroni technique; (2) a sequential Bonferroni technique; and (3) a sequential approach to control the false discovery rate proposed by Y. Benjamini and Y. Hochberg (1995). Explains advantages of the Benjamini and Hochberg…

Reviews some of the criticisms of contemporary practice regarding the use of statistical tests. Presents a brief overview of effect indices. Reviews related practices within seven volumes of "School Psychology Quarterly." Results show that contemporary authors continue to use and interpret statistical significance tests inappropriately. Explores…

Computational and plotting problems are often encountered with the Johnson-Neyman analysis of covariance procedure (P. Johnson and J. Neyman, 1936) when using three covariates. Use of an appropriate design and contrast matrix for the general linear model and the Mathematica software system to overcome these problems is described. (SLD)