Controversy over the proper place of significance testing within scientific methodology has continued for some time. The suggestion that effect sizes are more important than whether results are significant is presented. Effect size can be defined as an estimate of how much of the dependent variable is accounted for by the independent variables.…

The use of multiple comparisons in analysis of variance (ANOVA) is discussed. It is argued that experimentwise Type I error rate inflation can be serious and that its influences are often unnoticed in ANOVA applications. Both classical balanced omnibus and orthogonal planned contrast tests inflate experimentwise error to an identifiable maximum.…

Two strategies, derived from J. P. Schaffer (1986), were compared as tests of significance for a complete set of planned orthogonal contrasts. The procedures both maintain an experimentwise error rate at or below alpha, but differ in the manner in which they test the contrast with the largest observed difference. One approach proceeds directly to…

Generalizability or invariance procedures have been known for over three decades. Through the years, these procedures have not been widely discussed or employed. One reason for the lack of use is that most of the articles on invariance procedures have been mathematically oriented. The mathematical orientation of research articles and the lack of…

Describes a set of five programs providing robust techniques that work well when the assumption of conventional analysis of variance have been violated. (Author/RC)

Four different extensions to McNemar's problem concerning the hypothesis of equal probabilities for the unlike pairs of correlated binary variables are considered, each for testing simultaneous equality of proportions of unlike pairs in c independent populations of correlated binary variables, but each under different assumptions and/or additional…

A method of applying the discriminant function to correlated samples was discussed for the researcher interested in utilizing multivariate statistics to pre-post data. By finding the linear combination that maximizes differences in the groups, the t-statistic can be computed for correlated samples. (Author)

Reading researchers should be encouraged to include assessments of practical significance in all their journal articles, reviews of research, technical reports, and dissertations. The tendency has been to base the integration of data entirely on the results of tests for the significance of differences, overlooking the assessment of practical…

Common applications of the part correlation coefficient are in causal regression models and estimation of suppressor variable effects. However, there is no statistical test of the significance of the difference between a zero-order correlation and a part correlation, nor between a pair of part correlations. Hotelling's t is used for contrasting:…

An instrument was developed to measure the attitudes of public school board members on issues such as the expenditure of additional local money for various programs and services, the determination of teacher raises, and required minimum proficiency tests for high school graduation. A total of 66 completed questionnaires was usable from the 112…

The power of a statistical test is, in part, a function of the reliability of the dependable variable being analyzed. The substitution of sigma square divided by the reliability coefficient for sigma is proposed. This enables the researcher to incorporate dependent variable reliability information when determining the sample size required for a…

Two well known directional (one-tailed) tests of significance, mean difference and correlation coefficient, are presented within the multiple linear regression framework. Adjustments on the computed probability level are indicated. The case for a directional interaction research hypothesis is defended. Conservative adjustments on the computed…

The primary purpose of the present study was to investigate empirically the effect of multiple hypothesis testing on error rates in factorial ANOVA designs under a variety of controlled conditions. The per comparison, per experiment, and experimentwise error rates were investigated for three hypothesis testing procedures. The specific conditions…