Two stage multiple-comparison procedures give an exact solution to problems of power and Type I errors, but require equal sample sizes in the first stage. This paper suggests a method of evaluating the experimentwise Type I error probability when the first stage has unequal sample sizes. (Author/BW)

Discusses difficulties encountered in use of the Scheffe procedure to locate the most significant parametric function within a linear statistical model that has been tested and rejected by, for example, analysis of variance. A solution to the problems is presented. (TJH)

The dangers of equating "statistical significance" with "real world" significance are summarized. When a finding is said to have "statistical significance," it means only that the same results would be likely to occur again if the study were repeated, not that the finding has any true personal or societal importance. (VW)

Designed to measure end-users' efficacy in online searching based on their presearch experience with printed literature retrieval systems for the search topic, this experiment examined differences between manual searches preceding electronic searches and vice versa. The results were not statistically significant due to the small sample size.…

Investigates sample size requirements needed to achieve various levels of statistical power using posttest-only, gain-score, and analysis of covariance designs in evaluating training interventions. Results indicate the power to detect true effects differ according to type of design, correlation between pre- and posttest, and size of effect due to…

Procedures are described for determining the statistical significance of a set of ratings made on bidirectional (B) scales. B and its statistical significance can be determined on samples of items or raters. The statistical significance of a mean of B values can be assessed by applying a normal approximation test. (Author/DWH)

The Galois-lattice is a graphic method for representing all possible developmental phases to reach a given total knowledge via different partial knowledge structures. Algorithms are proposed for incorporating statistical analysis into the Galois-lattice method. A comparison to the Rasch model and application for educational research are given. (BS)

Available approaches for determing significant differences between various groups are considered for use when the homogeneity of slopes precludes standard analysis of covariance. The advantages and statistical procedures for relating to a reference group are presented and criteria are suggested for choosing the best groups. (Author)

This article presents a system for avoiding Type I error increases when increasing the number of contrasts computed. Based on the Bonferroni inequality, the procedure corrects for the number of contrasts tested. Although conservative, the Bonferroni system is recommended for its flexibility, simplicity, and generality. (Author/BS)

While Bonferroni procedures control the risk of Type I errors, their cost is loss of power. Ordered Bonferroni procedures conserve power for more important tests while sacrificing power for less important tests. Both costs and benefits should be considered when choosing weights for individual tests and the overall level of Type I error protection.…

The effects of some restraints not included in the classical assumptions of the F- and H-Test (e.g., correlation of mean and sample size) were examined in a simulation design. Also simulated was a situation in which two assumptions were not met simultaneously. (Author/BW)

After presenting a general linear model as a framework for discussion, this paper reviews five methodology errors that occur in educational research: (1) the use of stepwise methods; (2) the failure to consider in result interpretation the context specificity of analytic weights (e.g., regression beta weights, factor pattern coefficients,…

Two types of qualitative dependent variables are presented for use in counseling research: choices from an unordered set of categorical alternatives and ordered, categorical counseling outcomes. To investigate school choice behavior, the conditional logit model and analysis are introduced. The conditional logit model can include the attributes of…

This paper addresses the state of the art regarding the use of statistical significance tests (SSTs). How social science research will be conducted in the future is impacted directly by current debates regarding hypothesis testing. This paper: (1) briefly explicates the current debate on hypothesis testing; (2) reviews the newly published report…

This study was conducted to investigate the equivalence of scores from paper-and-pencil (P&P) tests and computerized tests (CTs) through meta-analysis of primary studies using both kinds of tests. For this synthesis, 51 primary studies were selected, resulting in 226 effect sizes. The first synthesis was a typical meta-analysis that treated…