This study describes a longitudinal design (following subjects described in Rutherford & Rogers [2003, "Journal of Autism and Developmental Disorder", 33, 289-302]) to test for predictors of pretend play competence in a group of children with autism. We tested the hypothesis that developmental change in pretend play performance can be predicted by…

Two Monte Carlo studies were conducted to examine the sensitivity of goodness of fit indexes to lack of measurement invariance at 3 commonly tested levels: factor loadings, intercepts, and residual variances. Standardized root mean square residual (SRMR) appears to be more sensitive to lack of invariance in factor loadings than in intercepts or…

In this case study, based on the reported rediscovery of the Ivory-billed Woodpecker in April 2005, students examine a real-world example of the scientific process and explore the practical implications of their conclusions. The case tells the story of Brad Murky, a student and research assistant who must decide whether the available evidence is…

This study extends previous research by Dilworth by examining antecedents of both positive and negative family-to-work spillover--a long-neglected area of research. It also uses an extended definition of domestic labor that includes emotion work and status enhancement. Using data from a random sample of dual-earner couples, the study found gender…

IQ scores provide the best general predictor of success in education, job training, and work. However, there are many ways in which IQ scores can be increased, for instance by means of retesting or participation in learning potential training programs. What is the nature of these score gains? Jensen [Jensen, A. R. (1998a). "The g factor: The…

The use of directional and nondirectional hypothesis testing was examined from the perspectives of textbooks, journal articles, and members of editorial boards. Three widely used statistical texts were reviewed in terms of how directional and nondirectional tests of significance were presented. Texts reviewed were written by: (1) D. E. Hinkle, W.…

Sequential probability ratio testing (PRT), which usually is applied in situations requiring a decision between two simple hypotheses or a single decision point, is extended to include situations involving k decision points and [(k + 1)-choose-2] sets of simultaneous, simple hypotheses, where k>1. The multiple-decision point or…

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 relationship between residence and fertility among women living in rural and urban areas of Costa Rica was examined. (JC)

A description of a fully operational AI-CAI system which incorporates artificial intelligence techniques to perform question answering, hypothesis verification, and theory formation activities in the domain of electronic trouble-shooting. (Author)

This paper assesses the relative merits of numerical and textual approaches to the study of international events. While enjoying a much longer history, numerical approaches have certain representational drawbacks that do not apply to textual approaches. Textual models provide a more adequate descriptive foundation for the study of international…

This paper is concerned with estimation and hypothesis testing of treatment effects in nonequivalent control group designs with the assumption that in the absence of treatment effects, natural growth conforms to a particular class of continuous growth models. Point estimation, interval estimation, and hypothesis testing procedures were developed…

This paper discusses four criteria for selecting covariates when utilizing the analysis of covariance in quasiexperimental research: completeness, causation, independence, and fallibility. Completeness is the extent to which the known or suspected sources of bias are accounted for by covariates used in an experiment. Causation is the requirement…

The mathematical extension from scalars to matrices as a prerequisite for univariate to multivariate generalizations of statistical concepts and methods is discussed. One reason for several alternative techniques is the multitude of ways to generalize from univariate concepts to multivariate concepts. The additional complexity, and lack of…

The present investigation developed power curves for two parametric and two nonparametric procedures for testing the equality of population variances. Both normal and non-normal distributions were considered for the two group design with equal and unequal sample frequencies. The results indicated that when population distributions differed only in…