Tests of homogeneity of means and covariance matrices for multivariate incomplete data

Existing test statistics for assessing whether incomplete data represent a missing completely at random sample from a single population are based on a normal likelihood rationale and effectively test for homogeneity of means and covariances across missing data patterns. The likelihood approach cannot be implemented adequately if a pattern of missing data contains very few subjects. A generalized least squares rationale is used to develop parallel tests that are expected to be more stable in small samples. Three factors were varied for a simulation: number of variables, percent missing completely at random, and sample size. One thousand data sets were simulated for each condition. The generalized least squares test of homogeneity of means performed close to an ideal Type I error rate for most of the conditions. The generalized least squares test of homogeneity of covariance matrices and a combined test performed quite well also.Preliminary results on this research were presented at the 1999 Western Psychological Association convention, Irvine, CA, and in the UCLA Statistics Preprint No. 265 (http://www.stat.ucla.edu). The assistance of Ke-Hai Yuan and several anonymous reviewers is gratefully acknowledged.     

On robusiness of the normal-theory based asymptotic distributions of three reliability coefficient estimates

This paper studies the asymptotic distributions of three reliability coefficient estimates: Sample coefficient alpha, the reliability estimate of a composite score following a factor analysis, and the estimate of the maximal reliability of a linear combination of item scores following a factor analysis. Results indicate that the asymptotic distribution for each of the coefficient estimates, obtained based on a normal sampling distribution, is still valid within a large class of nonnormal distributions. Therefore, a formula for calculating the standard error of the sample coefficient alpha, recently obtained by van Zyl, Neudecker and Nel, applies to other reliability coefficients and can still be used even with skewed and kurtotic data such as are typical in the social and behavioral sciences.This research was supported by grants DA01070 and DA00017 from the National Institute on Drug Abuse and a University of North Texas faculty research grant. We would like to thank the Associate Editor and two reviewers for suggestions that helped to improve the paper.     

项目反应时间的对数偏正态模型

近年来,项目反应时间数据的建模是心理和教育测量领域的热门方向之一。针对反应时间的对数正态模型和Box-Cox正态模型的不足,本文在van der Linden的分层模型框架下基于偏正态分布建立一个反应时间的对数线性模型,并成功给出模型参数估计的马尔科夫链蒙特卡罗（Markov Chain Monte Carlo, MCMC）算法。模拟研究和实例分析的结果均表明,与对数正态模型和Box-Cox正态模型相比,对数偏正态模型表现出更加优良的拟合效果,具有更强的灵活性和适用性。     

The Scandal of Deduction

This article provides the first comprehensive reconstruction and analysis of Hintikka’s attempt to obtain a measure of the information yield of deductive inferences. The reconstruction is detailed by necessity due to the originality of Hintikka’s contribution. The analysis will turn out to be destructive. It dismisses Hintikka’s distinction between surface information and depth information as being of any utility towards obtaining a measure of the information yield of deductive inferences. Hintikka is right to identify the failure of canonical information theory to give an account of the information yield of deductions as a scandal, however this article demonstrates that his attempt to provide such an account fails. It fails primarily because it applies to only a restricted set of deductions in the polyadic predicate calculus, and fails to apply at all to the deductions in the monadic predicate calculus and the propositional calculus. Some corollaries of these facts are a number of undesirable and counterintuitive results concerning the proposed relation of linguistic meaning (and hence synonymy) with surface information. Some of these results will be seen to contradict Hintikka’s stated aims, whilst others are seen to be false. The consequence is that the problem of obtaining a measure of the information yield of deductive inferences remains an open one. The failure of Hintikka’s proposal will suggest that a purely syntactic approach to the problem be abandoned in favour of an intrinsically semantic one.     

师范生心理素质的结构及特征

该研究以山东师范大学和鲁东大学7个不同专业的1000名大四学生为被试．运用师范生心理素质问卷进行正式测试,采用Amos4．0统计软件对数据进行验证性因素分析。结果表明,师范生心理素质的合理的结构应是一阶九因素二阶三因素的结构,数据与理论模型拟合较好。结果还表明,男女生在非权势性因素的得分差异显著,文理科学生在责任心和客观性因素的得分差异显著。     

师范毕业生师范素质的调查与研究

采用自编问卷对师范毕业生的师范素质进行了调查,结果显示,测量总体在性别方面的方差分析结果无差异显著性。各系毕业生与中小学教师在教育机智、学业诊断、学生管理、教学策略以及总均分上,方差分析结果均呈显著性差异,表明师范毕业生的师范素质训练不容乐观。     

师范生心理素质评价体系的研究

用经过信度和效度检验的量表研究师范生的心理素质,表明师范生心理素质内涵丰富,包含人多内容,不同成分有着不同的贡献率,其中具有相对突出的重要成分是心理健康水平,人格特征,认知方式、元认知、智力和教育实践和知识。     

《中国青少年心理健康素质调查表》的区分效度研究

采用《中国青少年心理健康素质调查表》调查了天津市425名正常和115名有心理问题大学生的心理健康素质,结果表明：正常组大学生的人际素质、个性素质、自我、应对风格和适应等分量表得分都高于有心理问题组大学生且具有显著差异,而动力系统、认知风格、归因风格分量表得分差异不显著。比较分析研究结果说明《中国青少年心理健康素质调查表》在区分正常和有心理问题大学生的心理健康素质方面可靠、有效。     

Estimating Gait Stability: Asymmetrical Loading Effects Measured Using Margin of Stability and Local Dynamic Stability

Changes to intersegmental locomotor control patterns may affect body stability. Our study aimed to (a) characterize upper body dynamic stability in response to the unilateral addition of mass to the lower extremity and (b) evaluate the efficacy of 2 different stability measures commonly used in the literature to detect resulting symmetrical step pattern modifications across the weighted segments (spatial) and between epochs of the gait cycle (temporal). Young adults walked on a treadmill while unloaded or with weights applied unilaterally to their foot, shank, or thigh. Both margin of stability and local dynamic stability (LDS) estimates detected similar trends of distal segment weighting resulting in more unstable upper body movement compared to proximal weighting; however only LDS detected anteroposterior changes in upper body stability over time.     

师范生职业使命感与学业满意度及生活满意度的关系：人生意义感的作用

采取职业使命感量表、人生意义感量表、学业满意度量表和生活满意度量表对679名免费师范生进行调查,考察免费师范生的职业使命感与其学业满意度和生活满意度的关系,以及人生意义感在其关系中的作用。结果表明:(1)师范生的职业使命感不存在性别和年级差异。(2)师范生的职业使命感对其人生意义体验、学业满意度和生活满意度均存在显著的预测作用。(3)人生意义体验在职业使命感与学业满意度之间起显著的部分中介作用;人生意义体验也在职业使命感与生活满意度之间起显著的部分中介作用。(4)人生意义寻求在职业使命感与学业满意度、生活满意度之间的调节作用未得到支持;人生意义寻求在人生意义体验与学业满意度、生活满意度之间的调节作用也未得到支持,这可能体现了中西文化的差异。