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arXiv 2005.08749stat.MEcs.LG
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从观测数据和有限实验数据中学习调整集

Learning Adjustment Sets from Observational and Limited Experimental Data

University of Pittsburgh(匹兹堡大学)

Sofia Triantafillou, Gregory Cooper

摘要:

由于混杂因素,从观察数据中估计因果效应并不总是可能的。确定一组适当的协变量(调整集)并调整其影响可以消除混杂偏倚;但是,通常无法仅从观察数据中确定此类集。实验数据没有混杂偏倚,但通常受样本量的限制,因此可能产生不精确的估计值。此外,实验数据通常包括有限的协变量集,因此对潜在系统的因果结构提供有限的见解。在这项工作中,我们介绍了一种方法,结合大型观测和有限的实验数据,以确定调整集,提高因果效应的估计。该方法通过计算实验数据的边际似然来识别调整集(如果可能的话),给出潜在调整集的观测导出的先验概率。通过这种方式,该方法可以做出仅使用所有观察和实验数据中的条件依赖性和独立性是不可能的推断。我们表明,该方法成功地识别调整集,提高了因果效应估计模拟数据,它有时可以作出额外的推论相比,最先进的方法相结合的实验和观测数据。

英文摘要:

Estimating causal effects from observational data is not always possible due to confounding. Identifying a set of appropriate covariates (adjustment set) and adjusting for their influence can remove confounding bias; however, such a set is typically not identifiable from observational data alone. Experimental data do not have confounding bias, but are typically limited in sample size and can therefore yield imprecise estimates. Furthermore, experimental data often include a limited set of covariates, and therefore provide limited insight into the causal structure of the underlying system. In this work we introduce a method that combines large observational and limited experimental data to identify adjustment sets and improve the estimation of causal effects. The method identifies an adjustment set (if possible) by calculating the marginal likelihood for the experimental data given observationally-derived prior probabilities of potential adjustmen sets. In this way, the method can make inferences that are not possible using only the conditional dependencies and independencies in all the observational and experimental data. We show that the method successfully identifies adjustment sets and improves causal effect estimation in simulated data, and it can sometimes make additional inferences when compared to state-of-the-art methods for combining experimental and observational data.

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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