Factorial structure of short scales measuring manic-depression in Kuwaiti undergraduates

A sample of 202 Kuwaiti college students (63 men and 139 women; Mage=21.6 yr., SD=2.4) responded to the Thalbourne, et al.'s Manic-Depressiveness Scale. In a factor analysis with a varimax rotation, 14 of 18 items had significant loadings (>.3) on the first factor, including 8 items of the original depression scale. 6 items significantly loaded on the second factor, including 3 items of the original mania scale. This did not match the hypothetical structure of the scale.     

Predicting attitudes toward operation Iraqi freedom

98 male and female college students ranging in age from 17 to 22 years (M= 19.2, SD= 1.1) were administered a questionnaire that contained Altemeyer's 20-item Right-Wing Authoritarianism Scale (RWA), questions about the legitimacy of the 2000 presidential election, Mayton's Physical Nonviolence Subscale, and a scale designed to measure attitudes toward Operation Iraqi Freedom. RWA scores, perceptions of the legitimacy of the 2000 presidential election, and scores on the Physical Nonviolence subscale were independent predictors of attitudes toward Operation Iraqi Freedom. In addition, those who had higher RWA scores were more likely to perceive the 2000 presidential election as legitimate. There was no significant correlation between RWA scores and attitudes toward physical nonviolence.     

Preliminary study of police experience of misconduct in their colleagues

A pilot study of 33 male and 2 female municipal police officers, most between 30 and 40 years old, found that those whose colleagues more often engage in misconduct experience more excitement and more stress in their work.     

Personal information in searching for faces

Participants searched for a target on a television monitor either after they viewed pictures and received physical information about the target or received that information augmented by personal information. Based on a levels of processing perspective we predicted that the addition of personal information would stimulate deeper processing and result in better identification performance. Personal information did increase identification accuracy, as anticipated. Personal information also increased the duration of time spent on the search task relative to a distractor task, suggesting that personal information may have done more than deepen the processing at the time of encoding. In the current climate of terrorism, this increase in identification performance via a surveillance camera has clear applied significance.     

The impact of the Samaritan centres on suicide in Scotland

A study of Scottish suicide rates from 1958 to 1981 showed no evidence for a preventive effect from the growth in the number of Samaritan centres.     

On the existence and uniqueness of JML estimates for the partial credit model

A necessary and sufficient condition is given in this paper for the existence and uniqueness of the maximum likelihood (the so-called joint maximum likelihood) estimate of the parameters of the Partial Credit Model. This condition is stated in terms of a structural property of the pattern of the data matrix that can be easily verified on the basis of a simple iterative procedure. The result is proved by using an argument of Haberman (1977). The author wishes to thank the Editor and the anonymous reviewers for their comments that helped to substantially improve the final version of this paper. This research was supported in part by a MURST grant (ex 60%).     

Psychometric Modeling of response speed and accuracy with mixed and conditional regression

Human performance in cognitive testing and experimental psychology is expressed in terms of response speed and accuracy. Data analysis is often limited to either speed or accuracy, and/or to crude summary measures like mean response time (RT) or the percentage correct responses. This paper proposes the use of mixed regression for the psychometric modeling of response speed and accuracy in testing and experiments. Mixed logistic regression of response accuracy extends logistic item response theory modeling to multidimensional models with covariates and interactions. Mixed linear regression of response time extends mixed ANOVA to unbalanced designs with covariates and heterogeneity of variance. Related to mixed regression is conditional regression, which requires no normality assumption, but is limited to unidimensional models. Mixed and conditional methods are both applied to an experimental study of mental rotation. Univariate and bivariate analyzes show how within-subject correlation between response and RT can be distinguished from between-subject correlation, and how latent traits can be detected, given careful item design or content analysis. It is concluded that both response and RT must be recorded in cognitive testing, and that mixed regression is a versatile method for analyzing test data.I am grateful to Rogier Donders for putting his data at my disposal.     

Likelihood inference on the underlying structure of IRT models

The assumptions underlying item response theory (IRT) models may be expressed as a set of equality and inequality constraints on the parameters of a latent class model. It is well known that the same assumptions imply that the parameters of the manifest distribution have to satisfy a more complicated set of inequality constraints which, however, are necessary but not sufficient. In this paper, we describe how the theory for likelihood-based inference under equality and inequality constraints may be used to test the underlying assumptions of IRT models. It turns out that the analysis based directly on the latent structure is simpler and more flexible. In particular, we indicate how several interesting extensions of the Rasch model may be obtained by partial relaxation of the basic constraints. An application to a data set provided by Educational Testing Service is used to illustrate the approach.We thank Dr. Gorman and Dr. Rogers of the Educational Testing Service for providing the data analyzed in Section 4. We also thank three reviewers for comments and suggestions.This revised article was published online in August 2005 with the PDF paginated correctly.     

Suppositions, extensionality, and conditionals: a critique of the mental model theory of Johnson-Laird And Byrne (2002)

P. N. Johnson-Laird and R. M. J. Byrne proposed an influential theory of conditionals in which mental models represent logical possibilities and inferences are drawn from the extensions of possibilities that are used to represent conditionals. In this article, the authors argue that the extensional semantics underlying this theory is equivalent to that of the material, truth-functional conditional, at least for what they term "basic" conditionals, concerning arbitrary problem content. On the basis of both logical argument and psychological evidence, the authors propose that this approach is fundamentally mistaken and that conditionals must be viewed within a suppositional theory based on what philosophical logicians call the Ramsey test. The Johnson-Laird and Byrne theory is critically examined with respect to its account of basic conditionals, nonbasic conditionals, and counterfactuals.