On Bayesian estimation in unrestricted factor analysis

It is shown that the common and unique variance estimates produced by Martin & McDonald's Bayesian estimation procedure for the unrestricted common factor model have a predictable sum which is always greater than the maximum likelihood estimate of the total variance. This fact is used to justify a suggested simple alternative method of specifying the Bayesian parameters required by the procedure.     

Some approximate tests for repeated measurement designs

Four approximate tests are considered for repeated measurement designs in which observations are multivariate normal with arbitrary covariance matrices. In these tests traditional within-subject mean square ratios are compared with critical values derived fromF distributions with adjusted degrees of freedom. Two of them—the approximate and the improved general approximate (IGA) tests—behave adequately in terms of Type I error. Generally, the IGA test functions better than the approximate test, however the latter involves less computations. In regards to power, the IGA test may compete with one multivariate procedure when the assumptions of the latter are tenable.The author wishes to thank Garrett K. Mandeville for his careful reading of the final version of the paper.     

智力与性格因素影响汉族和白族中小学生品德发展的研究

本研究通过对448名汉族和328名白族中小学生的智力因素、性格因素与其品德发展的相关分析和方差分析,证明：（1）智力因素是影响学生品德发展的一个重要因素;（2）性格因素与学生的品德发展具有广泛的相关,品德优良学生的性格素质显著优于品德中等和品德不良的学生。     

WEIRDness abounds! Sample characteristics,restricted variance,and why they matter for international selection and assessment research

There is increasing awareness that reliance on samples from Western, Educated, Industrialized, Rich, Democratic (WEIRD) countries may have skewed our view of human phenomena. Nowhere is this more true than in international selection and assessment (ISA) research. In the present paper, we describe a way of understanding the impact of WEIRDness on ISA phenomena: restricted variance (RV). The WEIRDness problem is usually one of cross level interactions in which a country-level variable (e.g., individualism/collectivism) might moderate the relationship between two individual-level variables. RV can help to see not only where such cross level interactions might exist, but also provide a specific, mathematical reason for their existence. We use several examples from IJSA and related sources to illustrate the role of RV in ISA-based WEIRDness.     

Gleaning in the field of dual scaling

Some historical background and preliminary technical information are first presented, and then a number of hidden, but important, methodological aspects of dual scaling are illustrated and discussed: normed versus projected weights, the amount of information accounted for by each solution, a perfect solution to the problem of multidimensional unfolding, multidimensional quantification space, graphical display, number-of-option problems, option standardization versus item standardization, and asymmetry of symmetric (dual) scaling. Contrary to the common perception that dual scaling and similar quantification methods are now mathematically transparent, the present study demonstrates how much more needs to be clarified for routine use of the method to arrive at valid conclusions. Data analysis must be carried out in such a way that common sense, intuition and sound logic will prevail.Presidential Address delivered at the Annual Meeting of the Psychometric Society, Banff Centre for Conferences, Banff, Alberta, Canada, June 27–30, 1996. The work has been supported in part by a grant from the Natural Sciences and Engineering Research Council of Canada. I am grateful to Ira Nishisato for his comments, Ingram Olkin and Yoshio Takane for important references, and Liqun Xu for computational help.     

Risky choice as a function of amount and variance in food supply.

In Experiment 1, 4 rats earned their daily food ration by choosing on a trials basis between a "risky" and a "riskless" lever. The risky lever produced either 15 45-mg food pellets or no pellets, and on average provided five pellets per choice. The riskless lever always produced three pellets. Across conditions, the number of trials per session was varied. Body weight and choice of the risky lever decreased as the number of trials per session decreased, even though body weight could only be defended by increased choice of the risky lever. In Experiment 2, trials per session were fixed, but the number of pellets delivered by the risky and riskless levers was either at the same level as in Experiment 1 or tripled from those levels. Now choice of the risky lever was inversely related to the size of reinforcement and to body weight. The results of these experiments show that risk aversion covaries with the amount of food available in a session and the daily variance in the amount of food earned.     

An algorithm for comparing medians

An algorithm is presented for computing a test statistic for comparing medians based on a small-sample size estimate of the variance of the usual sample median.     

短时距估计中的标量特性

使用单任务研究程序,采用预期式研究范式和再现时距的研究方法,从心理物理学的视角,通过三个实验系统地考查了人类短时距估计的标量特性、变异源、时距估计中的转换点和韦伯函数的形态等问题。结果表明,刺激物的运动、变化、速度和物理时距是被试进行短时距估计的重要变异源;被试在实验中表现出高估较短时距和低估较长时距的倾向,时距估计的转换点为11.1s;计时过程中得到的韦伯函数是个分段连续函数, 韦伯函数的拐点有两个12s和21s,这两点与本研究得到的时距估计转换点具有部分一致性     

测评中的共同方法偏差

共同方法变异是指由于测量方法而非所测构想造成的变异。共同方法变异会对测评和测评间的相关产生严重影响,甚至会使研究导致错误结论。本文介绍了学界对共同方法偏差的研究,内容包括：(1)共同方法偏差在多大程度上和以何种方式影响测评研究结果;(2)共同方法偏差的潜在来源及其程序控制。     

Practicing Elements Versus Practicing Coordination: Changes in the Structure of Variance

ABSTRACT

The authors explored effects of practice of a 2-finger accurate force production task on components of finger force variance quantified within the uncontrolled manifold (UCM) hypothesis, V_UCM, that had no effect on total force and V_ORT that affected total force. A variable task with graded instability was designed to encourage use of variable solutions. Two groups of subjects (n = 9 each) were tested prior to a 1.5-hr practice session, after the session, and 2 weeks later (retention test). Group 1 practiced 1 finger at a time, while Group 2 practiced the task with 2 fingers (index and middle) pressing together. Both groups showed comparable improvements in the performance indices. Both groups showed a decrease in V_ORT, while only Group 2 showed an increase in V_UCM. These effects persisted during the retention test. The results show that practicing elements and practicing redundant groups of elements may lead to similar changes in performance (i.e., in the variability of the total force produced by the set of fingers), accompanied by dramatically different changes in the structure of variance: A drop in V_UCM after the single-finger practice and an increase following the 2-finger practice. The strong retention effects promise applications of the method to rehabilitation.