Resampling probability values for differences between two independent indices of ordinal variation and consensus

A permutation method is presented to calculate resampling probability values for differences between two independent indices of ordinal variation and consensus.     

Exact and resampling probability values for measures associated with ordered r by c contingency tables

Permutation procedures to compute exact and resampling probability values associated with measures of association for ordered r x c contingency tables are described. Comparisons with asymptotic probability values demonstrated that exact and resampling permutation procedures were preferred for sparse contingency tables.     

A measure of effect size for r x c contingency tables

Goodman and Kruskal's tau measure of categorical association is advanced as a replacement for conventional measures of effect size for r x c contingency tables. Goodman and Kruskal's tau is an asymmetric measure of categorical association which is based entirely on the observed data and possesses a clear interpretation in terms of proportional reduction in error. Comparisons with conventional measures of effect size based on chi-squared such as Pearson's phi2, Tschuprow's T2, and Cramer's V2 demonstrate the advantages of employing tau as a measure of effect size.     

Minority students of color and the psychology graduate pipeline: disquieting and encouraging trends, 1989-2003

Trends since 1989 in the minority graduate pipeline in psychology are examined, with special focus on trends in recent years. Encouraging trends generally outweigh troubling ones at lower levels of the pipeline. However, in recent years disquieting trends dominate at the higher pipeline levels. Promising trends include a rise in the percentage (to nearly 25%) of minority psychology students receiving the bachelor's degree and a rise to more than 20% receiving the master's degree. Troubling trends include the stalling of growth in minority PhD degree receipt since 1999 and the lack of growth in the percentage of African American and Hispanic/Latino(a) students entering PhD departments. Given the mixed findings, one of the highest priorities for psychology must be continued and persistent efforts to develop practices and policies that enhance recruitment, high levels of achievement, and degree receipt for students of color.     

Taxometric Investigation of PTSD: data from two nationally representative samples

Current psychiatric nosology depicts posttraumatic stress disorder (PTSD) as a discrete diagnostic category. However, only one study has examined the latent structure of PTSD, and this study suggested that PTSD may be more accurately conceptualized as an extreme reaction to traumatic life events rather than a discrete clinical syndrome. To build on the existing literature base, the present research examined the latent structure of posttraumatic stress reactions by applying three taxometric procedures (MAXEIG, MAMBAC, and L-Mode) to data collected from large nationally representative samples of women (ns = 2684 and 3033) and adolescents (n = 3775). Results consistently provided evidence for a dimensional PTSD solution across samples and statistical procedures. These findings have important implications for the theory, assessment, and investigation of posttraumatic stress reactions.     

The role of functionality in the mental representations of engineering students: some differences in the early stages of expertise

As engineers gain experience and become experts in their domain, the structure and content of their knowledge changes. Two studies are presented that examine differences in knowledge representation among freshman and senior engineering students. The first study examines recall of mechanical devices and chunking of components, and the second examines whether seniors represent devices in a more abstract functional manner than do freshmen. The most prominent differences between these 2 groups involve their representation of the functioning of groups of electromechanical components and how these groups of components interact to produce device behavior. Seniors are better able to construct coherent representations of devices by focusing on the function of sets of components in the device. The findings from these studies highlight some ways in which the structure and content of mental representations of design knowledge differ during the early stages of expertise acquisition.     

Withholding inputs in team contexts: member composition, interaction processes, evaluation structure, and social loafing

Social loafing was observed as a naturally occurring process in project teams of students working together for 3-4 months. The authors assessed the contributions that member composition (i.e., relational dissimilarity and knowledge, skills, and abilities; KSAs), perceptions of the team's interaction processes (i.e., dispensability and the fairness of the decision-making procedures), and the team's evaluation structure (i.e., identifiability) make toward understanding loafing behavior. Identifiability moderated the impact of dispensability on loafing but not the impact of fairness on loafing. Perceptions of fairness were negatively related to the extent that participants loafed within their team. Specific aspects of relational dissimilarity were positively associated with perceptions of dispensability and negatively associated with perceptions of fairness, whereas KSAs were negatively associated with perceptions of dispensability.     

Self-monitoring and consumer psychology

Research on the relations between self-monitoring differences and two important areas of consumer behavior, reactions to specific advertising approaches and product evaluation strategies, is reviewed and evaluated. First, research on the responsiveness of high and low self-monitors to image-oriented and product-quality-based advertising attempts is addressed. Although findings generally indicate that high self-monitors are more responsive to image-oriented ads and that low self-monitors are more responsive to quality-based appeals, these results have not been robust. Possible reasons for this inconsistency are explored. Second, research on the means by which high and low self-monitors evaluate consumer products is examined. Findings suggest that when judging product quality, low self-monitors tend to rely on product performance and high self-monitors more likely use the product's image-enhancing capabilities. Additionally, research indicates that self-image/product-image congruency is generally a more important concern for low self-monitors, but high and low self-monitors' differential reliance on this congruency might be moderated by the situations in which the product is typically used. Additional possible delimiting conditions of these general findings are discussed.     

MMPI-2 at the crossroads: aging technology or radical retrofitting?

Paradigmatic shifts are uncommon in psychological assessment, which is often steeped more in tradition than innovative practices. The introduction of the Restructured Clinical (RC) Scales by Tellegen et al. (2003) represents a radical shift in the development and validation of the MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989). In broadening the debate over the merit of the RC Scales, in this article, we examine current challenges to MMPI-2 interpretation including issues with discriminant validity and imprecision (e.g., standard errors of measurement).We evaluate the RC alternative in the context of these interpretive challenges. Although we note several improvements, the incremental validity for MMPI-2 interpretative statements remains to be established. MMPI-2 researchers may wish to test several innovative models for their comparative strengths in establishing scale properties and providing empirically based interpretations.