Some properties of two measures of multivariate association

Two kinds of measures of multivariate association, based on Wilks' and the Bartlett-Nanda-Pillai trace criterionV, respectively, are compared in terms of properties of the univariateR ² which they generalize. A unified set of derivations of the properties is provided which are self-contained and not restricted to decompositions in canonical variates. One conclusion is that asymmetric index based on allows generalization of the multiplicative decomposition ofR ² in terms of squared partial correlations, but not the additive decomposition in terms of squared semipartial correlations, while the reverse is true for anasymmetric index based onV.We are indebted to Jos M. F. ten Berge for some fruitful discussions.     

Should I Drive Today? Development of a daily driving decisions model for older adults

BackgroundOlder adults in communities make daily decisions about how to meet their transportation needs so they can access services and stay socially connected. With the aging of populations in developed countries, the travel decisions of older adults will have increasing impacts. Research studies have identified different sets of factors that contribute to certain travel decisions, but little research has been directed towards understanding how individuals select information from all available factors, what information they include in their decisions under different circumstances, and the processes they use in making their transportation decisions.MethodsThis exploratory study involved 20 men and 17 women, mean age 78.6 years (range 70–96), who drove weekly. All participants were involved in each phase of the 3-phase study. In Phase 1, a review of the literature and interviews with the participants was used to collect information, and inductive thematic analysis was employed to construct a draft conceptual model of older driver decision-making. In Phase 2, participants completed a stated preference task of written scenarios to demonstrate their decision-making strategies. Results were tabulated and used to refine a final Daily Driving Decisions model. In Phase 3, a card sorting decision task was used to test the model with participants.ResultsThe final dynamic Daily Driving Decisions Model was confirmed to describe decision processes used by the participants in making decisions about how they would meet their transportation needs. The model describes three categories of factors used in decisions, labelled Motivators, Constraint/Enablers and Context, each containing four attribute themes. A significant finding was the variable use of the same item to either constrain or enable the decision to drive depending on the variation of other factors in the scenario. Participants demonstrated use of compensatory and noncompensatory (heuristic, habitual) decision processes that were accommodated by the model.ConclusionThe proposed Daily Driving Decisions Model addresses a gap in our understanding of how older drivers make their decisions about meeting their transportation needs. The model presents a template for classifying the types of information used, ignored or discarded by older adults, and the pathways that they take to arrive at their decisions. The model provides opportunities for further research in testing the influence of other factors such as urban/rural residence, income, health status and culture on driving decisions. Further, the model can be used by practitioners to gain insight into the decision-making behaviours of individuals and to develop interventions to enhance their decision-making skills.     

围手术期抗菌药物合理使用与药品费用的相关性分析

通过对本地一所三级甲等医院进行的围手术期抗菌药物的干预对照研究,用SPSS软件对470个手术病例的调查资料进行了统计分析,加强抗菌药物的用药管理及进行用药干预,能在对住院时间和手术切口感染率无影响的同时,明显降低手术病例的药品费用,特别是抗茵药品的费用,减轻患者负担。     

消费决策中羊群行为的心理机制

羊群行为是消费市场上的一种典型现象,它是指在不确定情境中,消费者模仿他人进行消费决策的行为。本研究通过模拟消费情境对消费者羊群行为的心理机制进行研究。研究1通过操纵观点的强弱研究消费者的信息加工方式。结果发现,消费者的羊群行为是消费者采用一致性启发式或能力启发式的结果。研究2进一步通过操纵群体内部的一致性程度考察两种启发式的作用条件。结果表明,在群体内部一致性程度高的情况下,消费者倾向于采用一致性启发式,与大众决策保持一致;在群体内部一致性低的情况下,消费者倾向于采用能力启发式,与专家的决策保持一致。     

Making the illusory correlation effect appear and then disappear: The effects of increased learning

The acquisition of a negative evaluation of a fictitious minority social group in spite of the absence of any objective correlation between group membership and negative behaviours was described by Hamilton and Gifford (1976) Hamilton, D. L. and Gifford, R. K. 1976. Illusory correlation in intergroup perception: A cognitive basis of stereotypic judgments. Journal of Experimental Social Psychology, 12: 392–407. [Crossref], [Web of Science ®] , [Google Scholar] as an instance of an illusory correlation. We studied the acquisition and attenuation through time of this correlation learning effect. In two experiments we asked for participants’ judgements of two fictitious groups using an online version of a group membership belief paradigm. We tested how judgements of the two groups changed as a function of the amount of training they received. Results suggest that the perception of the illusory correlation effect is initially absent, emerges with intermediate amounts of absolute experience, but diminishes and is eliminated with increased experience. This illusory correlation effect can be considered to reflect incomplete learning rather than a bias due to information loss in judgements or distinctiveness.     

大学生亲社会倾向、亲社会推理以及它们的相关模式

采用《亲社会倾向测量》和《亲社会推理客观测量》研究了17至20岁大学生的六类亲社会倾向和亲社会推理的状况。发现大学生将利他的亲社会倾向列为六类倾向中的首位,接下来依次是紧急的、情绪性的、依从的、匿名的和公开的亲社会倾向;在亲社会推理五种类型中大学生选择比率最高的是内化价值定向的推理,接下来依次是刻板定向、需要定向和享乐主义定向的推理,所占比率最低的是赞扬定向的推理;六类亲社会倾向与亲社会推理之间具有特定的棚关模式．利他的和匿名的亲社会倾向与内化价值定向和刻板定向的推理正相关、与享乐主义定向及赞扬定向的推理负相关,公开的亲社会倾向与赞扬定向的推理正相关、与需要定向的推理负相关。跨文化比较证实,中美大学生的上述三个方面表现出一定的差异。     

Interval estimation for the intraclass correlation in dirichlet-multinomial data

When the underlying distribution is discrete with a limited number of categories, methods for interval estimation of the intraclass correlation which assume normality are theoretically inadequate for use. On the basis of large sample theory, this paper develops an asymptotic closed-form interval estimate of the intraclass correlation for the case where there is a natural score associated with each category. This paper employs Monte Carlo simulation to demonstrate that when the underlying intraclass correlation is large, the traditional interval estimator which assumes normality can be misleading. We find that when the number of classes is 20, the interval estimator proposed here can generally perform reasonably well in a variety of situations. This paper further notes that the proposed interval estimator is invariant with respect to a linear transformation. When the data are on a nominal scale, an extension of the proposed method to account for this case, as well as a discussion on the relationship between the intraclass correlation and a kappa-type measure defined here and on the limitation of the corresponding kappa-type estimator are given.The authors wish to thank the Editor, the Associate Editor, and the three referees for many valuable comments and suggestions to improve the clarity of this paper. The works for the first, the third, and the fourth authors were partially supported by grant #R01AR43025-01 from the National Institute of Arthritis and Musculoskeletal and Skin Diseases.     

Phenotypic and genotypic heterogeneity in gaucher disease: Implications for genetic counseling

Genetic counseling for Gaucher disease is complicated by the vast degree of clinical heterogeneity encountered in the disorder. Recent advances in our understanding of the molecular genetics of Gaucher disease are particularly relevant to genetic counseling. Although the identification of mutations in the glucocerebrosidase gene has enabled genotypic screening of Gaucher patients, the ability to reliably predict patient outcome on the basis of DNA studies is often limited. An appreciation of both the spectrum of clinical manifestations in Gaucher patients and the limitations of the available genotypic information is necessary when counseling patients, families and at-risk individuals.     

Linear relations amongk sets of variables

A family of solutions for linear relations amongk sets of variables is proposed. It is shown how these solutions apply fork=2, and how they can be generalized from there tok3.The family of solutions depends on three independent choices: (i) to what extent a solution may be influenced by differences in variances of components within each set; (ii) to what extent the sets may be differentially weighted with respect to their contribution to the solution—including orthogonality constraints; (iii) whether or not individual sets of variables may be replaced by an orthogonal and unit normalized basis.Solutions are compared with respect to their optimality properties. For each solution the appropriate stationary equations are given. For one example it is shown how the determinantal equation of the stationary equations can be interpreted.