An in-class activity is described that can be used not only to motivate hypothesis testing, but also to understand and compute the p-value and power in a statistical test. (Contains 3 figures.)

Multiple-hypothesis testing in the context of a correlation matrix is used to compare the statistical power of the original Bonferroni with six modified Bonferroni procedures that control the overall Type I error rate. Three definitions of statistical power are considered: (1) the ability to detect at least one true relationship; (2) the ability…

The U.S. Army Research Institute for the Behavioral and Social Sciences has developed a wide range of statistical models to test hypotheses generated in relation to an equally wide range of measurement and evaluation situations. The randomized block (RB) design has traditionally been a preferred model for much psychological research. The RB has…

To study the relationship of education to economic growth for the state of Iowa, the hypothesis that increasing the level of education for the labor force would lead to higher levels of income or economic growth was tested for the period from 1950-1967. The Cobb-Douglas production was used to evaluate the relationship. The function used labor…

The statistical analysis of processing tree models is advanced by showing how the parameters of estimation and hypothesis testing, based on the likelihood functions, can be accomplished by adapting the expectation-maximization (EM) algorithm. The adaptation makes it easy to program a personal computer to accomplish the stages of statistical…

This study developed and investigated an empirical sampling distribution of the congruence coefficient. The effects of sample size, number of variables, and population value of the congruence coefficient on the sampling distribution of the congruence coefficient were examined. Sample data were generated on the basis of the common factor model and…

The testing of a priori contrasts, post hoc contrasts, and experimental error rates are discussed. Methods for controlling the experimental error rate for a set of a priori contrasts tested simultaneously have been developed by Dunnett, Dunn, Sidak, and Krishnaiah. Each of these methods is discussed and contrasted as to applicability, power, and…

A procedure was developed within hypothesis-testing logic that allows researchers to support a hypothesis that has traditionally been the statistical or null hypothesis. Four activities involved in attainment of this goal were discussed: (1) development of statistical logic needed to define the sampling distribution associated with the hypothesis…

The results of reanalyses of statistical procedures used in the class-size meta-analyses by Glass and Smith are reported. The analyses suggest that the use of suboptimal statistical methods did not greatly affect the results of the meta-analyses by Glass and Smith. (Author/PN)

Evaluations involving nonrandom assignment to treatment or control groups are vulnerable to an accidental or intentional confounding of a selection effect with the treatment effect. Two techniques, discriminant analysis and base expectancy analysis, permit separate estimation of the selection and treatment effects in the final results. (Author/CTM)

A subset of Statistical Process Control (SPC) methodology known as Control Charting is introduced. SPC methodology is a collection of graphical and inferential statistics techniques used to study the progress of phenomena over time. The types of control charts covered are the null X (mean), R (Range), X (individual observations), MR (moving…

The purpose of this study was to compare the results of an analysis of covariance design to a method developed by the authors called within-class regression. Application of this statistical method can be to any quasiexperimental design with a large number of groups. A test of statistical significance to use with the within-class regression…

This study tests the general hypothesis that preschool experience has a measurable effect upon children's noncognitive development between the time they enter and the time they leave the preschool program. The California Preschool Competency Scale (CPSCS) was administered to 4-year-old children in a prekindergarten program (PreK) in the fall of…

To determine whether a significant relationship exists between educational funding and pupil achievement as measured by Science Research Associates standardized test scores, the author of this study conducted a statistical analysis of the top one-third and bottom one-third of Virginia's 142 school districts. The 30 districts selected were chosen…

This paper reports the results of a Monte Carlo investigation of Type I errors in the single group repeated measures design where multiple measures are collected from each observational unit at each measurement occasion. The Type I error of three multivariate tests were examined. These were the doubly multivariate F test, the multivariate mixed…