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arXiv 2303.08528stat.ME
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将预测分布转化为有信息的先验

Translating predictive distributions into informative priors

MRC Biostatistics Unit, University of Cambridge(剑桥大学MRC生物统计学单位)

Andrew A. Manderson, Robert J. B. Goudie

AI总结:

本文提出将可观测量或模型导出的边际量的先验分布转化为有信息的联合先验,通过参数化先验分布和优化超参数来减少预测分布与给定分布的差异。

摘要:

当复杂贝叶斯模型表现出不合理的行为时,一种解决方案是将可用信息整合成有信息的先验。挑战在于,先验信息通常只适用于可观测量或某些模型导出的边际量,而非直接关联到模型中的(通常为隐含)参数。我们提出了一种方法,将可用的先验信息(以可观察量或模型导出的边际量的 elicited 分布形式)转化为有信息的联合先验。我们的方法基于一个参数化的先验分布类,其超参数尚未确定,并最小化给定的 elicited 分布与对应的先验预测分布之间的差异。我们采用全局的、多阶段的贝叶斯优化过程来定位超参数的最佳值。三个例子展示了我们的方法:一个治愈分数生存模型,其中删失意味着可观测量在先验上是混合的离散/连续量;一个涉及 $R^{2}$(模型导出的量)的先验信息的场景;以及一个非线性回归模型。

英文摘要:

When complex Bayesian models exhibit implausible behaviour, one solution is to assemble available information into an informative prior. Challenges arise as prior information is often only available for the observable quantity, or some model-derived marginal quantity, rather than directly pertaining to the (usually latent) parameters in our model. We propose a method for translating available prior information, in the form of an elicited distribution for the observable or model-derived marginal quantity, into an informative joint prior. Our approach proceeds given a parametric class of prior distributions with as yet undetermined hyperparameters, and minimises the difference between the supplied elicited distribution and corresponding prior predictive distribution. We employ a global, multi-stage Bayesian optimisation procedure to locate optimal values for the hyperparameters. Three examples illustrate our approach: a cure-fraction survival model, where censoring implies that the observable quantity is _a priori_ a mixed discrete/continuous quantity; a setting in which prior information pertains to $R^{2}$ -- a model-derived quantity; and a nonlinear regression model.

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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