arXivDaily arXiv每日学术速递 周一至周五更新
arXiv math/0703123math.STstat.TH
收藏

可能零概率单元列联表的代数贝叶斯分析

Algebraic Bayesian analysis of contingency tables with possibly zero-probability cells

Guido Consonni, Giovanni Pistone

摘要:

在本文中,我们考虑了贝叶斯分析的列联表允许的可能性,细胞可能有概率为零。从这个意义上说,我们离开标准的对数线性模型,隐含地假设一个积极的约束。我们的方法使我们考虑混合模型的列联表,其中的成分的混合物,我们称之为模型实例,有不同的支持。我们依靠多项式代数的思想来识别各种模型实例。我们还提供了一种方法来分配先验概率的模型的每个实例,以及描述的方法,用于构建先验的参数空间的每个实例。我们说明我们的方法,通过一个$5 \times 2$表,涉及两个结构零,以及零计数。我们得到的结果表明,我们的分析可能会导致的结论是实质性的不同,将获得在一个标准的框架,其中的可能性零概率细胞没有明确占。

英文摘要:

In this paper we consider a Bayesian analysis of contingency tables allowing for the possibility that cells may have probability zero. In this sense we depart from standard log-linear modeling that implicitly assumes a positivity constraint. Our approach leads us to consider mixture models for contingency tables, where the components of the mixture, which we call model-instances, have distinct support. We rely on ideas from polynomial algebra in order to identify the various model instances. We also provide a method to assign prior probabilities to each instance of the model, as well as describing methods for constructing priors on the parameter space of each instance. We illustrate our methodology through a $5 \times 2$ table involving two structural zeros, as well as a zero count. The results we obtain show that our analysis may lead to conclusions that are substantively different from those that would obtain in a standard framework, wherein the possibility of zero-probability cells is not explicitly accounted for.

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。

↑