Application of model-selection criteria to some problems in multivariate analysis

A review of model-selection criteria is presented, with a view toward showing their similarities. It is suggested that some problems treated by sequences of hypothesis tests may be more expeditiously treated by the application of model-selection criteria. Consideration is given to application of model-selection criteria to some problems of multivariate analysis, especially the clustering of variables, factor analysis and, more generally, describing a complex of variables.     

Retrospective questions and correlations

In survey research it is not uncommon to ask questions of the following type: “How many times did you undertake actiona in reference periodT of length τ?.” The relationship is established between τ and the correlation of the number of reported actions with some background variable. To this end it is assumed that the process of actions satisfies a renewal model with individual heterogeneity. Also a model has to be formulated for possible recall effects. Applications are given in the field of medical consumption.     

Factor analysis by instrumental variables methods

Three alternative estimation procedures for factor analysis based on the instrumental variables method are presented. These procedures are justified by the method of least squares. Formulas for asymptotic standard errors of factor loadings are derived. The procedures are empirically compared to the method of maximum likelihood. The conclusion, based on the data used in this study, is that two of the procedures seem to work well.     

Initial response to rape: The impact of factors within the rape situation

The relationship between specific aspects of the rape situation and immediate post-rape measures of depression, fear, anxiety, and social and interpersonal functioning in 50 recent victims of sexual assault was examined. The data failed to reveal any significant relationships between rape situation variables (e.g., stranger vs. known assailant, weapon vs. no weapon) and the nature or severity of the victims' psychological response. It is emphasized that this negative finding contradicts previous and current clinical lore, and has a number of implications for the assessment and treatment of rape victims.This research was supported by a grant from the National Institute of Mental Health (MH#29692) to the first two authors.     

Life stories managing chronic illness: Young adults’ lived experiences with type 1 diabetes

This study aimed to characterise diabetes management experiences of South African young adults living with well-controlled type 1 diabetes (n = 8, female = 5, male = 3, age range = 20–25). The young adults told life stories managing their type 1 diabetes. Thematic analysis revealed the young adults to construct personal identities as people living with type 1 diabetes, to mostly utilise emotion-focused management strategies and social support for successful living with type 1 diabetes. Behavioural health strategies appear important for living well with this chronic insulin deficiency condition.     

国外心理契约破坏及结果变量与调节变量：述评与展望

心理契约破坏是个体对组织未能履行其在心理契约中应承担责任的认知评价。文章首先结合以往研究探讨了心理契约破坏与相应结果变量的关系,然后探讨了调节变量的作用,最后从被试群体、研究方法及理论模型的构建上对未来研究进行了展望。     

Performed or observed keyboard actions affect pianists' judgements of relative pitch

Action can affect visual perception if the action's expected sensory effects resemble a concurrent unstable or deviant event. To determine whether action can also change auditory perception, participants were required to play pairs of octave-ambiguous tones by pressing successive keys on a piano or computer keyboard and to judge whether each pitch interval was rising or falling. Both pianists and nonpianist musicians gave significantly more “rising” responses when the order of key presses was left-to-right than when it was right-to-left, in accord with the pitch mapping of the piano. However, the effect was much larger in pianists. Pianists showed a similarly large effect when they passively observed the experimenter pressing keys on a piano keyboard, as long as the keyboard faced the participant. The results suggest that acquired action–effect associations can affect auditory perceptual judgement.     

Effects of stimulus order on discrimination processes in comparative and equality judgements: Data and models

In typical discrimination experiments, participants are presented with a constant standard and a variable comparison stimulus and their task is to judge which of these two stimuli is larger (comparative judgement). In these experiments, discrimination sensitivity depends on the temporal order of these stimuli (Type B effect) and is usually higher when the standard precedes rather than follows the comparison. Here, we outline how two models of stimulus discrimination can account for the Type B effect, namely the weighted difference model (or basic Sensation Weighting model) and the Internal Reference Model. For both models, the predicted psychometric functions for comparative judgements as well as for equality judgements, in which participants indicate whether they perceived the two stimuli to be equal or not equal, are derived and it is shown that the models also predict a Type B effect for equality judgements. In the empirical part, the models' predictions are evaluated. To this end, participants performed a duration discrimination task with comparative judgements and with equality judgements. In line with the models' predictions, a Type B effect was observed for both judgement types. In addition, a time-order error, as indicated by shifts of the psychometric functions, and differences in response times were observed only for the equality judgement. Since both models entail distinct additional predictions, it seems worthwhile for future research to unite the two models into one conceptual framework.     

High-dimensional maximum marginal likelihood item factor analysis by adaptive quadrature

Although the Bock–Aitkin likelihood-based estimation method for factor analysis of dichotomous item response data has important advantages over classical analysis of item tetrachoric correlations, a serious limitation of the method is its reliance on fixed-point Gauss-Hermite (G-H) quadrature in the solution of the likelihood equations and likelihood-ratio tests. When the number of latent dimensions is large, computational considerations require that the number of quadrature points per dimension be few. But with large numbers of items, the dispersion of the likelihood, given the response pattern, becomes so small that the likelihood cannot be accurately evaluated with the sparse fixed points in the latent space. In this paper, we demonstrate that substantial improvement in accuracy can be obtained by adapting the quadrature points to the location and dispersion of the likelihood surfaces corresponding to each distinct pattern in the data. In particular, we show that adaptive G-H quadrature, combined with mean and covariance adjustments at each iteration of an EM algorithm, produces an accurate fast-converging solution with as few as two points per dimension. Evaluations of this method with simulated data are shown to yield accurate recovery of the generating factor loadings for models of upto eight dimensions. Unlike an earlier application of adaptive Gibbs sampling to this problem by Meng and Schilling, the simulations also confirm the validity of the present method in calculating likelihood-ratio chi-square statistics for determining the number of factors required in the model. Finally, we apply the method to a sample of real data from a test of teacher qualifications.