arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2202.06200cs.IRcs.AI
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基于邻域丰富的对比学习改进图协同过滤

Improving Graph Collaborative Filtering with Neighborhood-enriched Contrastive Learning

School of Information, Renmin University of China(中国人民大学信息学院);Gaoling School of Artificial Intelligence, Renmin University of China(中国人民大学高瓴人工智能学院);Beijing Key Laboratory of Big Data Management and Analysis Methods(北京市大数据管理与分析方法重点实验室)

Zihan Lin, Changxin Tian, Yupeng Hou, Wayne Xin Zhao

摘要:

最近,图协同过滤方法已被提出作为一种有效的推荐方法,它可以捕捉用户的偏好,通过建模的用户项目交互图。为了降低数据稀疏性的影响,将对比学习引入到图协同过滤中以提高性能。然而,这些方法通常通过随机抽样来构造对比对,忽略了用户(或项目)之间的相邻关系,未能充分利用对比学习的潜力进行推荐。为了解决上述问题,我们提出了一种新的对比学习方法,命名为邻居丰富的对比学习,命名为NCL,显式地将潜在的邻居到对比对。具体来说,我们分别从图结构和语义空间引入用户(或项目)的邻居。对于交互图上的结构邻居,我们开发了一种新的结构对比目标,将用户(或项目)及其结构邻居视为正对比对。在实现中,用户(或项目)和邻居的表示对应于不同GNN层的输出。此外,为了挖掘语义空间中潜在的邻居关系,我们假设具有相似表征的用户都在语义邻居中,并将这些语义邻居纳入原型对比目标。提出的NCL可以用EM算法优化,并推广到图协同过滤方法。在5个公共数据集上的实验结果表明了该方法的有效性,在Yelp和Amazon-book数据集上的性能分别比基于竞争图的协同过滤模型提高了26%和17%。我们的代码可在https://github.com/RUCAIBox/NCL上获得。

英文摘要:

Recently, graph collaborative filtering methods have been proposed as an effective recommendation approach, which can capture users' preference over items by modeling the user-item interaction graphs. In order to reduce the influence of data sparsity, contrastive learning is adopted in graph collaborative filtering for enhancing the performance. However, these methods typically construct the contrastive pairs by random sampling, which neglect the neighboring relations among users (or items) and fail to fully exploit the potential of contrastive learning for recommendation. To tackle the above issue, we propose a novel contrastive learning approach, named Neighborhood-enriched Contrastive Learning, named NCL, which explicitly incorporates the potential neighbors into contrastive pairs. Specifically, we introduce the neighbors of a user (or an item) from graph structure and semantic space respectively. For the structural neighbors on the interaction graph, we develop a novel structure-contrastive objective that regards users (or items) and their structural neighbors as positive contrastive pairs. In implementation, the representations of users (or items) and neighbors correspond to the outputs of different GNN layers. Furthermore, to excavate the potential neighbor relation in semantic space, we assume that users with similar representations are within the semantic neighborhood, and incorporate these semantic neighbors into the prototype-contrastive objective. The proposed NCL can be optimized with EM algorithm and generalized to apply to graph collaborative filtering methods. Extensive experiments on five public datasets demonstrate the effectiveness of the proposed NCL, notably with 26% and 17% performance gain over a competitive graph collaborative filtering base model on the Yelp and Amazon-book datasets respectively. Our code is available at: https://github.com/RUCAIBox/NCL.

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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