arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2404.19620cs.LGcs.IRstat.ML
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注意邻域效应:在干扰下建模选择偏差

Be Aware of the Neighborhood Effect: Modeling Selection Bias under Interference

Peking University(北京大学);University of Science and Technology of China(中国科学技术大学);Beijing Technology and Business University(北京工商大学)

Haoxuan Li, Chunyuan Zheng, Sihao Ding, Peng Wu, Zhi Geng, Fuli Feng, Xiangnan He

AI总结:

本文从因果推断视角将推荐系统中的邻域效应形式化为干扰问题,提出处理表示、理想损失及两个估计器,在同时存在选择偏差和邻域效应时实现无偏学习,并通过半合成与真实实验验证其有效性。

摘要:

推荐系统中的选择偏差来源于系统过滤的推荐过程和用户选择的交互过程。许多先前的研究专注于解决选择偏差以实现预测模型的无偏学习,但忽略了一个事实:给定用户-物品对的潜在结果可能会随着施加于其他用户-物品对的处理而变化,这被称为邻域效应。为了填补这一空白,本文从因果推断的视角将邻域效应正式形式化为一个干扰问题,并引入一种处理表示来捕捉邻域效应。在此基础上,我们提出了一种新颖的理想损失,可用于在存在邻域效应的情况下处理选择偏差。我们进一步开发了两个新的估计器来估计所提出的理想损失。我们从理论上建立了所提方法与先前忽略邻域效应的去偏方法之间的联系,表明当选择偏差和邻域效应同时存在时,所提方法能够实现无偏学习,而现有方法则是有偏的。我们进行了广泛的半合成和真实世界实验,以证明所提方法的有效性。

英文摘要:

Selection bias in recommender system arises from the recommendation process of system filtering and the interactive process of user selection. Many previous studies have focused on addressing selection bias to achieve unbiased learning of the prediction model, but ignore the fact that potential outcomes for a given user-item pair may vary with the treatments assigned to other user-item pairs, named neighborhood effect. To fill the gap, this paper formally formulates the neighborhood effect as an interference problem from the perspective of causal inference and introduces a treatment representation to capture the neighborhood effect. On this basis, we propose a novel ideal loss that can be used to deal with selection bias in the presence of neighborhood effect. We further develop two new estimators for estimating the proposed ideal loss. We theoretically establish the connection between the proposed and previous debiasing methods ignoring the neighborhood effect, showing that the proposed methods can achieve unbiased learning when both selection bias and neighborhood effect are present, while the existing methods are biased. Extensive semi-synthetic and real-world experiments are conducted to demonstrate the effectiveness of the proposed methods.

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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