In this paper we propose two interpretations for the discrimination parameter in the two-parameter logistic model (2PLM). The interpretations are based on the relation between the 2PLM and two stochastic models. In the first interpretation, the 2PLM is linked to a diffusion model so that the probability of absorption equals the 2PLM. The…

Bilingualism (Sanz, 2000), motivation (Pintrich, 1989), and language aptitude (Grigorenko, Sternberg, and Ehrman, 2000) are crucial individual differences that contribute to successful adult language learning. Since Gardner's (1985) seminal work on motivation, many studies have shown that motivation is dynamic and that it affects language…

The term "environment-based education" describes a form of school-based environmental education in which an instructor uses the local environment as a context for integrating subjects and a source of real world learning experiences. Despite the growing body of evidence that supports the educational efficacy of this instructional approach and its…

Multiple samples of university students (N = 1,537) completed the Almost Perfect Scale-Revised (APS-R; R. B. Slaney, M. Mobley, J. Trippi, J. Ashby, & D. G. Johnson, 1996). Cluster analyses, cross-validated discriminant function analyses, and receiver operating characteristic curves for sensitivity and specificity of APS-R scores were used to…

We examined how strongly motivation, metacognition, and psychopathology acted as predictors of learning disabilities (LD). The results from five studies suggested that level of motivation (as shown through self-efficacy, motivational force, task avoidance, goal commitment, or self-concept) was highly accurate in classifying students with or at…

The purpose of this study was to extend understanding of the effects of aging on the female voice by obtaining measures of both acoustic and respiratory-based performance in groups of 18-30, 40-49, 50-59, 60-69, and 70-79-year-old subjects. Acoustic measures of speaking fundamental frequency (SFF), pitch sigma, jitter, shimmer, and signal-to-noise…

The purpose of this research is to understand the effect of the presence of children in the home on the quality of life of clergy and clergy spouses. A survey research design is used involving a random sample of 232 clergy and 169 clergy spouses. Data collected pertaining to selected variables in the ABC-X model of family stress. Discriminant…

Uncorrectable skew and heteroscedasticity are among the "lemons" of psychological data, yet many important variables naturally exhibit these properties. For scales with a lower and upper bound, a suitable candidate for models is the beta distribution, which is very flexible and models skew quite well. The authors present…

This study explores whether the brain can discriminate degrees of semantic congruency during wakefulness and sleep. Experiment 1 was conducted during wakefulness to test degrees of congruency by means of N400 amplitude. In Experiment 2, the same paradigm was applied to a different group of participants during natural night sleep. Stimuli were 108…

A study investigated the vocal intensity of interviewers and the gender of interviewees to test a speech accommodation theory of behavioral reactions to speech style, while simultaneously determining whether previous research is corroborated in the context of the employment interview. Multiple discriminant analysis of 34 interviews (13 males and…

Three methods of transforming unordered categorical response variables are described. One is a method using dummy binary variables. The second method analyzes all categorical variables simultaneously and is based on an eigenanalysis of frequency patterns scaled relative to within-groups variance, jointly developed by J. E. Overall and J. A.…

This study tests the hypothesis that resistance to interference as measured by Stroop Color and Word Test is related to psychopathology. College student subjects were classified into three groups on the basis of their Minnesota Multiphasic Personality Inventory (MMPI) profile high points. Subjects' cognitive interference scores significantly…

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…

Predictive discriminant analysis involves a technique used in multivariate classification, i.e., in predicting membership in well-defined groups for units on which multiple measures are available. The validation (assessment) of group membership predictions pertains to two problems: estimating true proportions of correct classifications (i.e., hit…