测试英语词汇的广度、深度和强度

自98年Laufer两次进行广度结合强度的三层面英语词汇知识研究后,Laufer et al于2004年两次进行了四层面词汇知识研究,首次提出并正在进行词汇广度结合强度的计算机机测的研究工作。在词汇研究领域原有的广度和深度上,又开辟了一条新的道路。文章试讨论80年代以来国内外就测试英语词汇的广度、深度和强度的主要研究,尝试探讨这些研究对我们英语词汇测试研究与词汇学习的启示。     

Rényi statistics for testing composite hypotheses in general exponential models

We introduce a family of Rényi statistics of orders r?∈?R for testing composite hypotheses in general exponential models, as alternatives to the previously considered generalized likelihood ratio (GLR) statistic and generalized Wald statistic. If appropriately normalized exponential models converge in a specific sense when the sample size (observation window) tends to infinity, and if the hypothesis is regular, then these statistics are shown to be χ²-distributed under the hypothesis. The corresponding Rényi tests are shown to be consistent. The exact sizes and powers of asymptotically α-size Rényi, GLR and generalized Wald tests are evaluated for a concrete hypothesis about a bivariate Lévy process and moderate observation windows. In this concrete situation the exact sizes of the Rényi test of the order r?=?2 practically coincide with those of the GLR and generalized Wald tests but the exact powers of the Rényi test are on average somewhat better.     

Robust Testing Procedures in Heteroscedastic Linear Models

There exist many studies which treat the robust tests in homoscedastic linear models. However, the robust testing procedure in heteroscedastic linear models has not been examined. In this article, three classes of testing procedures for testing subhypothesis in heteroscedastic linear models are developed. These are Wald-type, score-type, and drop-in dispersion tests. The asymptotic distributions of these tests are obtained under the null hypothesis and contiguous alternatives. For a robustness criterion, the maximum asymptotic bias of the level of the test for distributions in a shrinking contamination neighborhood is used and the most-efficient robust test is derived. Finally, the performance of these tests in small sample is studied by Monte Carlo simulation.     

Simple Tests for Exogeneity of a Binary Explanatory Variable in Count Data Regression Models

This article investigates power and size of some tests for exogeneity of a binary explanatory variable in count models by conducting extensive Monte Carlo simulations. The tests under consideration are Hausman contrast tests as well as univariate Wald tests, including a new test of notably easy implementation. Performance of the tests is explored under misspecification of the underlying model and under different conditions regarding the instruments. The results indicate that often the tests that are simpler to estimate outperform tests that are more demanding. This is especially the case for the new test.     

On Multi-Sided Permutation Tests

In fields such as clinical trials, the environment, epidemiology, genetics, pharmacology, social experiments, etc., situations in which the effect of a treatment can be positive on some individuals and negative on the rest may sometimes occur. In a two-sample design, this situation can be expressed by a response model where a random effect Δ in the alternative is such that , and . Such a situation is essentially different from the traditional two-sided test, in which the alternative is assumed to be active only on one of two directions. We consider alternatives in which two sub-alternatives (Δ < 0) and (Δ > 0) can be jointly active. In order to deal with such an atypical situation, we suggest to firstly apply two goodness-of-fit tests, one for the positive deviations from the empirical distribution function of control sample and the other for the negative, and then proceed with their nonparametric combination within a permutation framework. A simulation study inspects on properties of such a solution.     

A hypothesis testing procedure for the evaluation on the lifetime performance index of products with Burr XII distribution under progressive type I interval censoring

ABSTRACT

It is a very important topic these days to assessing the lifetime performance of products in manufacturing or service industries. Lifetime performance indices C_L is used to measure the larger-the-better type quality characteristics to evaluate the process performance for the improvement of quality and productivity. The lifetimes of products are assumed to have Burr XII distribution. The maximum likelihood estimator is used to estimate the lifetime performance index based on the progressive type I interval censored sample. The asymptotic distribution of this estimator is also developed. We use this estimator to build the new hypothesis testing algorithmic procedure with respect to a lower specification limit. Finally, two practical examples are given to illustrate the use of this testing algorithmic procedure to determine whether the process is capable.     

Using plausible values in secondary analysis in large-scale assessments

Plausible values are typically used in large-scale assessment studies, in particular, in the Trends in International Mathematics and Science Study and the Programme for International Student Assessment. Despite its large spread, there are still some questions regarding the use of plausible values and how such use affects statistical analyses. The aim of this paper is to demonstrate the role of plausible values in large-scale assessment surveys when multilevel modeling is used. Different user strategies concerning plausible values for multilevel models as well as means and variances are examined. The results show that some commonly used user strategies give incorrect results while others give reasonable estimates but incorrect standard errors. These findings are important for anyone wishing to make secondary analyses of large-scale assessment data, especially those interested in using multilevel models to analyze the data.     

培养研究生英语语言应用能力的教学体系研究

本文拟根据语言学、认知心理学理论 ,研究如何对研究生英语课程的教学体系 (包括教学内容、教学模式、教材建设、教学手段和方法、测试和语言评估体系及学生自主学习的方略等 )进行系统的研究和改革 ,充分运用和调动教与学的过程中各个环节的有利因素 ,致力培养和提高研究生的英语语言实际应用能力和利用英语为其专业发展服务的能力     

双语服务——大学图书馆的新选择

“双语服务”对大学图书馆的服务创新具有重要意义。图书馆实现双语服务,应该在环境视觉感官双语对照、日常接待礼仪用语、馆藏建设资源保障、参考咨询工作服务、人力资源管理、团队外语素质目标等方面的双语服务进行全面的设计与实施,以提升大学图书馆的信息服务水平。