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arXiv 1201.3702stat.ME
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两次F检验后单因素协方差分析中置信区间的覆盖概率

The coverage probability of confidence intervals in one-way analysis of covariance after two F tests

Waruni Abeysekera, Paul Kabaila, Oguzhan Yilmaz

摘要:

考虑协方差模型的单向分析。假设目标参数θ是给定协变量值的期望响应的指定线性对比。还假设感兴趣的推断是theta的1-alpha置信区间。提出了以下两个阶段的程序来确定模型的形式。在第1阶段,我们对斜率均为零的零假设与斜率不均为零的备择假设进行F检验。如果这个原假设被接受,那么我们假设斜率都为零;否则我们进行到阶段2。在第二阶段,我们对零假设进行F检验,零假设是斜率都相等,而备择假设是斜率不相等。如果这个原假设被接受,那么我们假设斜率都是相等的;否则不做这个假设。我们提出了一个一般的方法来检查这两个阶段的模型选择程序的覆盖概率上的一个间接构造的置信区间θ,与名义覆盖1-α的影响。这种方法被应用到一个数值例子,它表明,这个置信区间是完全不够的。

英文摘要:

Consider a one-way analysis of covariance model. Suppose that the parameter of interest theta is a specified linear contrast of the expected responses, for a given value of the covariate. Also suppose that the inference of interest is a 1-alpha confidence interval for theta. The following two-stage procedure has been proposed to determine the form of the model. In Stage 1, we carry out an F test of the null hypothesis that the slopes are all zero against the alternative hypothesis that they are not all zero. If this null hypothesis is accepted then we assume that the slopes are all zero; otherwise we proceed to Stage 2. In Stage 2, we carry out an F test of the null hypothesis that the slopes are all equal against the alternative hypothesis that they are not all equal. If this null hypothesis is accepted then we assume that the slopes are all equal; otherwise this assumption is not made. We present a general methodology for the examination of the effect of this two-stage model selection procedure on the coverage probability of a subsequently-constructed confidence interval for theta, with nominal coverage 1-alpha. This methodology is applied to a numerical example for which it is shown that this confidence interval is completely inadequate.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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