Subscores Based on Classical Test Theory: To Report or Not to Report

There is an increasing interest in reporting subscores, both at examinee level and at aggregate levels. However, it is important to ensure reasonable subscore performance in terms of high reliability and validity to minimize incorrect instructional and remediation decisions. This article employs a statistical measure based on classical test theory that is conceptually similar to the test reliability measure and can be used to determine when subscores have any added value over total scores. The usefulness of subscores is examined both at the level of the examinees and at the level of the institutions that the examinees belong to. The suggested approach is applied to two data sets from a basic skills test. The results provide little support in favor of reporting subscores for either examinees or institutions for the tests studied here.     

微分中值定理证明中辅助函数的一种简明构造法

微分中值定理是高等数学中最重要的基本定理之一,在国内外的教材以及数学专业杂志中,已有多种构造辅助函数 的证明方法.下面给出一种自然简明的辅助函数的构造法.     

S_1~4中具有零Gauss-Kronecker曲率的极大超曲面

构造了de Sitter空间S1中的一类具有零Gauss-Kronecker曲率的极大超曲面,它们是双曲空间H4中一类极小浸入曲面ξ:V→H 4的"Polar Map"像。     

T次方幂补数倒数的均值

研究任意正整数n的t次方幂补数倒数的均值性质，解决献[1]中，F.Smarandache教授提出的第29个问题，给出一个较强的渐近公式。     

研究钱在哪儿?

IF you fancy yourself as a globetrotting executive it makes sense to start as you mean to go on and hop on a plane to a business school. You can absorb a range of cultural experiences while gaining your MBA-what is more, it can be cheaper than studying at home.     

孔子的教育公平思想及其现代启示

教育公平问题是当今社会的热点问题。它要求政府、社会、教育者秉承公正的原则，对教育资源均衡配置，对受教育者平等对待。早在2500多年前，孔子就提出“有教无类”等教育主张，体现了他的教育公平思想。而这些主张在今天看来就意味着教育起点、教育过程、教育结果的公平。     

一道IMO试题的推广及应用

给出了一道第36届IMO不等式赛题的推广,并应用推广结论解证了一组不等式。     

Structural Equation Modeling With Unknown Population Distributions: Ridge Generalized Least Squares

This article proposes 2 classes of ridge generalized least squares (GLS) procedures for structural equation modeling (SEM) with unknown population distributions. The weight matrix for the first class of ridge GLS is obtained by combining the sample fourth-order moment matrix with the identity matrix. The weight matrix for the second class is obtained by combining the sample fourth-order moment matrix with its diagonal matrix. Empirical results indicate that, with data from an unknown population distribution, parameter estimates by ridge GLS can be much more accurate than those by either GLS or normal-distribution-based maximum likelihood; and standard errors of the parameter estimates also become more accurate in predicting the empirical ones. Rescaled and adjusted statistics are proposed for overall model evaluation, and they also perform much better than the default statistic following from the GLS method. The use of the ridge GLS procedures is illustrated with a real data set.     

含有上下导数的广义Cauchy中值定理及其逆定理

证明了含右上、右下、左上、左下导数的广义Cauchy中值定理及其逆定理。     

“Did I mean what I said?” — A reply to McCormick

In this note, I argue that the distinction between what one says and what one means by it is no more problematic (and no less) than the equally important distinction between evidence and theory. Both, I suggest, take a particular form in literate discourse.