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arXiv 2203.04403math.STstat.MEstat.TH
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依赖的恩赐:具有多个二元潜变量的离散模型的可识别性与几何结构

Blessing of Dependence: Identifiability and Geometry of Discrete Models with Multiple Binary Latent Variables

Yuqi Gu

AI总结:

本文提出代数技术研究含多个二元潜变量的离散模型可识别性,揭示依赖恩赐几何:最小条件下参数可识别当且仅当潜变量非独立,并可用于假设检验与模型设计。

摘要:

具有潜变量的离散统计模型的可识别性研究公认具有挑战性,然而它对模型的解释性和可靠性至关重要。本文提出了一种通用的代数技术来研究具有潜变量和图组件的离散模型的可识别性。具体而言,受收集多元分类数据的诊断测试的启发,我们关注具有多个二元潜变量的离散模型。我们考虑BLESS模型,在该模型中,潜变量之间可以存在任意依赖关系,而潜变量到观测的测量图呈“星-森林”形状。我们建立了可识别性的充分必要条件图准则,并揭示了一个有趣且或许令人惊讶的依赖恩赐几何结构:在通用可识别性的最小条件下,参数可识别当且仅当潜变量不是统计独立的。得益于这一理论,我们可以在边界情形下通过检验观测变量的边际独立性来进行可识别性的正式假设检验。除了BLESS模型,我们还利用该技术展示了一个更灵活的模型的可识别性和依赖恩赐几何结构,该模型具有超越星-森林的通用测量图。我们的结果为具有潜变量的图模型的统计性质提供了新的理解。它们还对设计测量二元潜特质的诊断测试或调查具有有用的启示。

英文摘要:

Identifiability of discrete statistical models with latent variables is known to be challenging to study, yet crucial to a model's interpretability and reliability. This work presents a general algebraic technique to investigate identifiability of discrete models with latent and graphical components. Specifically, motivated by diagnostic tests collecting multivariate categorical data, we focus on discrete models with multiple binary latent variables. We consider the BLESS model in which the latent variables can have arbitrary dependencies among themselves while the latent-to-observed measurement graph takes a "star-forest" shape. We establish necessary and sufficient graphical criteria for identifiability, and reveal an interesting and perhaps surprising geometry of blessing-of-dependence: under the minimal conditions for generic identifiability, the parameters are identifiable if and only if the latent variables are not statistically independent. Thanks to this theory, we can perform formal hypothesis tests of identifiability in the boundary case by testing marginal independence of the observed variables. In addition to the BLESS model, we also use the technique to show identifiability and the blessing-of-dependence geometry for a more flexible model, which has a general measurement graph beyond a start forest. Our results give new understanding of statistical properties of graphical models with latent variables. They also entail useful implications for designing diagnostic tests or surveys that measure binary latent traits.

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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