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arXiv 2406.19940stat.ME
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贝叶斯因子的闭式解功效与样本量计算

Closed-Form Power and Sample Size Calculations for Bayes Factors

Samuel Pawel, Leonhard Held

AI总结:

本文提出了无需蒙特卡洛模拟即可计算贝叶斯因子假设检验中功效与样本量的方法,在近似正态性假设下推导出闭式解公式,并开发了R包bfpwr以支持复杂先验下的研究设计。

摘要:

确定适当的样本量是研究设计的关键要素,且用于确定样本量的方法应与计划的分析方法保持一致。当计划的分析涉及贝叶斯因子假设检验时,通常期望样本量能确保在假设为真的条件下,获得表明对假设具有强有力证据的贝叶斯因子的概率足够高。在实践中,贝叶斯因子样本量确定通常使用计算密集型的蒙特卡洛模拟来执行。在此,我们总结了无需模拟即可确定样本量的替代方法。我们展示了在近似正态性假设下,如何以数值方法确定样本量,并为此提供了R包bfpwr。此外,我们确定了甚至可以以闭式解确定样本量的条件,由此产生新颖且易于使用的公式,这些公式还有助于培养直觉、实现渐近分析,并可用于混合贝叶斯/似然设计。进一步地,我们展示了如何在不进行模拟的情况下,针对更复杂的分析先验(如Jeffreys-Zellner-Siow先验或非局部正态矩先验)计算功效和样本量。来自医学和心理学的案例研究说明了研究人员如何使用我们的方法来设计信息丰富且具有成本效益的研究。

英文摘要:

Determining an appropriate sample size is a critical element of study design, and the method used to determine it should be consistent with the planned analysis. When the planned analysis involves Bayes factor hypothesis testing, the sample size is usually desired to ensure a sufficiently high probability of obtaining a Bayes factor indicating compelling evidence for a hypothesis, given that the hypothesis is true. In practice, Bayes factor sample size determination is typically performed using computationally intensive Monte Carlo simulation. Here, we summarize alternative approaches that enable sample size determination without simulation. We show how, under approximate normality assumptions, sample sizes can be determined numerically, and provide the R package bfpwr for this purpose. Additionally, we identify conditions under which sample sizes can even be determined in closed-form, resulting in novel, easy-to-use formulas that also help foster intuition, enable asymptotic analysis, and can also be used for hybrid Bayesian/likelihoodist design. Furthermore, we show how power and sample size can be computed without simulation for more complex analysis priors, such as Jeffreys-Zellner-Siow priors or non-local normal moment priors. Case studies from medicine and psychology illustrate how researchers can use our methods to design informative yet cost-efficient studies.

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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