Towards a theory of point optimal testing

This paper puts the case for the inclusion of point optimal tests in the econometrician's repertoire. They do not suit every testing situation but the current evidence, which is reviewed here, indicates that they can have extremely useful Small-sample power properties. As well as being most powerful at a nominated point in the alternative hypothesis parameter space, they may also have optimum power at a number of other points and indeed be uniformly most powerful when such a test exists. Point optimal tests can also be used to trace out the maxemum attainable power envelope for a given testing problem, thus providing a benchmark against which test procedures can be evaluated. In some cases, point optimal tests can be constructed from tests of simple null hypothesis against a simple alternative. For a wide range of models of interst to econometricians, this paper shows how one can check whether a point optimal test can be constructed in this way. When it cannot, one may wish to consider approximately point optimal tests. As an illustration, the approach is applied to the non-nested problem of testing for AR(1) distrubances against MA(1) distrubances in the linear regression model.     

Quark b2型运动心肺功能测试系统应用研究

研究目的:通过对Quark b2型运动心肺功能测试系统应用过程中相关问题的探讨,促进同行对运动心肺功能测试的深入认识以及对测试精度的更准确掌握。研究方法:对作者近年使用该型号仪器的经验进行总结并与国内外有关专家学者的研究报道进行印证比较,从中探索其内在的规律。研究结果:对本型号仪器的使用规程及其注意事项提出了相应的意见;对测试方案进行了综合比较,给出了相应的意见;对测试流程中最大摄氧量和无氧阈的判断标准给予了相应的建议;对测试指标的后期分析提出了自己的意见。研究结论:运动心肺功能测试是一项能综合反映人体心肺功能水平的有效测试技术,在逐步探索如何能够有效增加测试精度和效果的基础上,应该逐步推广该项测试技术。     

抽样调查下样本随机性的检验

 抽样调查下样本随机性的检验,不是考查抽样方法的优劣或是检查样本代表性的好坏,而是为了控制抽样调查的数据质量,检验所得样本和抽样方法的一致性,即调查机构是否严格按照抽样设计的要求去抽取样本。本文以等概率和不等概率抽样为例,揭示了如何利用相关辅助信息,构造检验统计量,进行样本随机性的检验。     

Reexamining a Model for Evaluating Information Center Success Using a Structural Equation Modeling Approach

Structural equation modeling is a technique that has been widely used for instrument validation and model testing in research in marketing and organizational behavior. The technique has also been introduced to MIS researchers and used in several studies recently reported in the literature. This article offers an example of how the technique can be used for instrument validation and model testing. The illustration is made through a reexamination of a model for evaluating information center (IC) success. With the growth of end-user computing, the success of an IC is more important than ever. Obtaining a valid model for measuring IC success is thus crucial to organizations with ICs. The results of this study highlight the importance of a strong theoretical base in developing such a valid model, and management should be cautious when using these models to assess the performance of their ICs.