Maximum likelihood estimation of polyserial correlations

This paper considers a multivariate normal model with one of the component variables observable only in polytomous form. The maximum likelihood approach is used for estimation of the parameters in the model. The Newton-Raphson algorithm is implemented to obtain the solution of the problem. Examples based on real and simulated data are reported.The research of the first author was supported in part by a research grant (DA01070) from the US Public Health Service. We are indebted to the referees and the editor for some very valuable comments and suggestions.     

Repeated measurements analysis of variance when the correlations have a certain pattern

Consider a repeated measurements study in which a single observation is taken at each oft(t > 2) equally spaced time points for each ofn subjects. This paper uses a result of Box to find the appropriate multiplicative correction term for the degrees of freedom in the analysis of variance table for the case when there is equal variability per time point, and when the correlation between observationsu time units apart is equal to ^u . For large values oft, the multiplicative correction has a lower bound approximately equal to 2.5/(t – 1).Dr. Fleiss is also with the Biometrics Research Unit of the New York State Psychiatric Institute. This work was supported in part by grant DE 04068 from the National Institute of Dental Research.     

Generalizations of the partial,part and bipartial canonical correlation analysis

Theg ₁- andg ₂-bipartial canonical correlation analyses are developed as generalizations of the partial, part, and bipartial canonical correlation analysis. Illustrative examples are provided.     

The second order approximation to sample influence curve in canonical correlation analysis

A second order approximation to the sample influence curve (SIC) in canonical correlation analysis has been derived in the literature. However, it does not seem satisfactory for some cases. In this paper, we present a more accurate second order approximation. As a particular case, the proposed method is exact for the SIC of the squared multiple correlation coefficient. An example is given. The authors are most grateful to the associate editor and three reviewers for valuable comments and suggestions which improved the presentation of the paper considerably. The first author was partly supported by a RGC earmarked research grant of Hong Kong.     

On the large sample distributions of modified sample biserial correlation coefficients

The asymptotic distributions of Brogden's and Lord's modified sample biserial correlation coefficients are derived. The asymptotic variances of these estimators are evaluated for bivariate normal populations and compared to the asymptotic variance of the maximum likelihood estimator.The author would like to thank the referees for several suggestions which improved the presentation of the paper.     

A scale-invariant treatment for recursive path models

A reparameterization is formulated that yields estimates of scale-invariant parameters in recursive path models with latent variables, and (asymptotically) correct standard errors, without the use of constrained optimization. The method is based on the logical structure of the reticular action model.     

Association coefficients of identity and proportionality for metric scales

Zegers' (1986) chance-corrected coefficients of association are derived by alternative methods. A different definition of chance correction is used. It is shown that our correction and that of Zegers are identical for large samples. Three possible assumptions for the derivation of metric coefficients are examined. The first, variable reflection, formulated by Zegers and ten Berge (1985), leads to coefficients that require chance-correction. Two other assumptions, zero covariance and covariance reflection, are proposed and it is shown that the latter two assumptions lead directly to coefficients of identity and proportionality that do not require chance correction (i.e., are identical to the Zegers, 1986, corrected coefficients).We are indebted to Robyn M. Dawes, Carnegie-Mellon University, for stimulating our interest in this project, and for helpful suggestions.     

应激性生活事件对森林公安民警心理健康的影响

目的:探讨应激性生活事件对森林公安民警心理健康的影响。方法:对160名森林公安民警采用症状自评量表和生活事件量表进行心理状态评定和生活事件调查分析,并分析应激性生活事件对森林公安民警心理健康的影响。结果:共发放问卷160份,收回有效问卷124份。森林公安民警的心理健康水平及各因子得分均高于国内常模,除强迫因子和精神病性因子外,差异不显著;应激性生活事件中家庭有关问题强度频度偏重,工作学习中的问题强度频度次之,社交及其它问题强度频度最轻;森林公安民警的应激性生活事件与心理健康水平成正相关,应激性生活事件能有效预测森林公安民警的心理健康状况。结论:森林公安民警的心理问题比较突出,应激性生活事件能有效预测森林公安民警的心理健康状况。     

Examining cognitive development from a conceptual change point of view: The framework theory approach

Sexual socialization refers to how, through social interaction, an individual acquires and internalizes culture-specific knowledge, values and attitudes about sexuality. Little, however, is known about how an individual's genetic characteristics modify this process, or if individuals gravitate towards specific environments according to their genetic characteristics. The aim was to explore whether adolescents' genetic predispositions modify environmental influences on peer-group sexual attitudes. Using a Finnish population-based sample of twins and their siblings (n = 9534), it was found that genetic effects influenced peer-group sexual attitudes in men (52%) and women (46%), thus offering evidence for gene–environment correlation. Men showed less restricted peer-group sexual attitudes than women. Some indications of different genes influencing environmental exposure in men and women were found.     

Illusory correlations revisited: The role of pseudocontingencies and working-memory capacity

Three experiments investigate illusory correlations in a feedback learning paradigm. Diverging from a standard paradigm, in which stimuli consist of joint observations of group–behaviour pairs, participants were asked to guess the group reference of positive and negative stimulus behaviours. They only knew that one group was larger than the other, and the stimulus series soon revealed that positive (negative) behaviours appeared more frequently in the stimulus series than negative (positive) behaviours. Regardless of whether feedback of the actual group reference was provided or not, the predominant valence was more strongly associated with the large than the small group. This illusory-correlation effect was evident in memory-based measures at the end of the stimulus series as well as in the online predictions during stimulus presentation. The strength of illusory correlations increased with decreasing working-memory capacity, operationalized either by an interpersonal differences measure or a cognitive-load manipulation. The occurrence of illusory correlations in the absence of joint observations about group–valence pairs (in the no-feedback condition and in the early phase of the online prediction task) can be explained as a reflection of pseudocontingency inferences.