A modification of Feldt's test of the equality of two dependent alpha coefficients

The available statistical tests of the equality of nonindependent alpha reliability coefficients require that the product of the number of test parts times the number of subjects be quite large—1000 or more. A modification of one of these tests is derived which avoids this limitation. Monte Carlo studies indicate that the modified test effectively controls the Type I error rate with as few as 2 or 3 test parts and 50 subjects. This means the modified test can be safely employed in comparisons between interrater reliabilities.     

Estimation of a Latent Variable Regression Growth Curve Model for Individuals Cross-Classified by Clusters

The cross-classified multiple membership latent variable regression (CCMM-LVR) model is a recent extension to the three-level latent variable regression (HM3-LVR) model which can be utilized for longitudinal data that contains individuals who changed clusters over time (for instance, student mobility across schools). The HM3-LVR model can include the initial status on growth effect as varying across those clusters and allows testing of more flexible hypotheses about the influence of initial status on growth and of factors that might impact that relationship, but only in the presence of pure clustering of participants within higher-level units. This Monte Carlo study was conducted to evaluate model estimation under a variety of conditions and to measure the impact of ignoring cross-classified data when estimating the incorrectly specified HM3-LVR model in a scenario in which true values for parameters are known. Furthermore, results from a real-data analysis were used to inform the design of the simulation. Overall, it would be recommended for researchers to utilize the CCMM-LVR model over the HM3-LVR model when individuals are cross-classified, and to use a bare minimum of more than 100 clustering units in order to avoid overestimation of the level-3 variance component estimates.     

Commentary on Coefficient Alpha: A Cautionary Tale

The general use of coefficient alpha to assess reliability should be discouraged on a number of grounds. The assumptions underlying coefficient alpha are unlikely to hold in practice, and violation of these assumptions can result in nontrivial negative or positive bias. Structural equation modeling was discussed as an informative process both to assess the assumptions underlying coefficient alpha and to estimate reliability     

大学生网络成瘾量表（修订版）的多元概化分析*

用多元概化理论考察大学生网络成瘾量表在大学生群体中应用的测量学性能。以随机测量模式的概化设计,针对1200名在校大学生进行问卷调查。结果显示双因子结构的相关程度在0.92以上,五因子结构的相关程度均在0.76~0.97间;整体量表的概化系数和可靠性指数均达到了0.94以上,而双因子结构各因子在0.90左右,五因子结构各因子均在0.74~0.85间。所以,整体量表及各因子在大学生群体中应用的信效度较高,可用作常模和标准参照测验;无论双因子还是五因子结构,CIAS-R各因子在分值比和项目数上,设计非常合理和完善。     

“新农合”对农民收入公平性的影响研究

利用卫生经济学中的洛伦茨曲线和基尼系数分析河南省"新农合"试点县农民收入公平性的变化,评价"新农合"筹资、补偿以及医疗费用负担对农民收入公平性的影响。为新农合的推广和发展提供政策建议,使"新农合"这一中国特色的医疗保障模式为农民更好的服务。     

一种新的等值准则及其适用范围的探讨

受假设检验方法的启发,该文引出了一种基于项目反应理论的新等值方法——平方根等值准则。它具有一些特点：定义式中答对、答错概率同时出现而不能互相替代;极易从0—1评分模式的版本转换到多级评分版本;它可以看成是Haebara等值准则的加权形式。以等值系数估计值的误差大小为衡量标准,以Wilcoxon符号秩检验为依据,大量的Monte Carlo模拟结果显示了一种有趣的现象,即等值方法的运用范围既与项目参数估计精度有关,又与等值系数A的范围有关,但与另一个等值系数B的范围无关。当项目参数估计精度较高或中等而A取值在0.9～1.3之间,新方法往往比Stocking_Lord方法和Haebara方法的估计误差小且有显著性差异,当项目参数估计精度较低时,而A从1.0～2.0时新方法都有优越性。     

The “Circular” Problems of Calculating Risk: Dealing with Consanguinity

An ongoing problem in the genetics clinic is the calculation of inbreeding coefficients and recurrence risks for complex pedigrees, particularly when multiple loops are present. Although the Human Genome Project promises information about more of our genes in the foreseeable future, the actual assignment of disease status to specific loci will continue at a slower pace, so that accurate risk calculations are needed. In the past few months several families with consanguinity were referred to us to confirm the calculations performed by the genetic counselor, and we became aware of some confusion in the field. We present here both (a) a clarification of definitions and concepts and (b) a review of how to perform the calculations, for several quantities (coefficient of relationship, coefficient of inbreeding, coefficient of kinship, and recurrence risk), in complex pedigrees. We discuss the availability of computer algorithms to assist in these calculations, and we encourage counselors to call on a reliable computer program for any but the simplest cases. At the same time, we reiterate our belief that computer algorithms do not relieve the counselor of the responsibility of knowing what to calculate and when.     

Tests for equality of several alpha coefficients when their sample estimates are dependent

In a variety of measurement situations, the researcher may wish to compare the reliabilities of several instruments administered to the same sample of subjects. This paper presents eleven statistical procedures which test the equality ofm coefficient alphas when the sample alpha coefficients are dependent. Several of the procedures are derived in detail, and numerical examples are given for two. Since all of the procedures depend on approximate asymptotic results, Monte Carlo methods are used to assess the accuracy of the procedures for sample sizes of 50, 100, and 200. Both control of Type I error and power are evaluated by computer simulation. Two of the procedures are unable to control Type I errors satisfactorily. The remaining nine procedures perform properly, but three are somewhat superior in power and Type I error control.A more detailed version of this paper is also available.     

概化理论在作文评分中的应用研究

概化理论是现代心理测量理论之一,该文简要地介绍了该理论的基本思想并用此理论对作文评分的误差控制问题进行了应用性探讨。研究中请６位评分员对２０名学生每人三种文体的作文用分项评分法进行评定。然后用ＧＥＮＯＶＡ软件的估计了作文评分中的评分员效应和题目效应,并对各种误差构成进行了分析比较。结果表明：在作文评分中,评分员勺最大,题目效应不明显。同时还发现,不同文体对评分误差有重要影响。论文文的评分误差最大,     

刺激-反应相容性的度量与运用

为了度量刺激－反应相容性的程度、预测汉字标准键盘编码输入法的易学性,根据Ｓ－Ｒ相容性中群体模板的定义,提出了相容性系数的概念及其计算方法,总结出运用相容性系数的值预测汉字标准键盘编码输入法易学性的方法。并通过实验室实验和实际测量对上述结果进行了验证