论文标题
将预测与非对比度学习联系
Link Prediction with Non-Contrastive Learning
论文作者
论文摘要
图形神经网络(GNN)空间中的近期焦点区域是图形自学学习(SSL),旨在在没有标记数据的情况下得出有用的节点表示。值得注意的是,许多最先进的图形SSL方法是对比方法,它们使用正面和负样本的组合来学习节点表示。由于负面采样(缓慢和模型灵敏度)的挑战,最近的文献引入了非对抗性方法,而这种方法仅使用阳性样品。尽管此类方法在节点级任务中显示出有希望的性能,但它们对链接预测任务的适用性,这些任务与预测节点对之间的链接存在有关(并且对建议系统上下文具有广泛的适用性)。在这项工作中,我们广泛评估了现有的非对比度方法的性能,以链接脱节性和归纳设置中的链接预测。尽管大多数现有的非对比度方法总体上的性能较差,但我们发现,令人惊讶的是,BGRL通常在换电环境中表现良好。但是,它在更现实的归纳环境中的性能较差,在这种环境中,该模型必须概括为与看不见的节点的链接/来自看不见的链接。我们发现,非对抗性模型倾向于过度贴上训练图,并使用此分析提出T-BGRL,这是一种新型的非对抗性框架,结合了廉价腐败以提高模型的概括能力。这种简单的修改强烈改善了我们数据集的5/6的电感性能,@50的命中率提高了120% - 所有速度都比其他非对抗性基线可比,并且比最出色的对比基线快14倍。我们的工作赋予了有关链接预测的非对抗性学习的有趣发现,并为未来的研究人员铺平了道路,以进一步扩展这一领域。
A recent focal area in the space of graph neural networks (GNNs) is graph self-supervised learning (SSL), which aims to derive useful node representations without labeled data. Notably, many state-of-the-art graph SSL methods are contrastive methods, which use a combination of positive and negative samples to learn node representations. Owing to challenges in negative sampling (slowness and model sensitivity), recent literature introduced non-contrastive methods, which instead only use positive samples. Though such methods have shown promising performance in node-level tasks, their suitability for link prediction tasks, which are concerned with predicting link existence between pairs of nodes (and have broad applicability to recommendation systems contexts) is yet unexplored. In this work, we extensively evaluate the performance of existing non-contrastive methods for link prediction in both transductive and inductive settings. While most existing non-contrastive methods perform poorly overall, we find that, surprisingly, BGRL generally performs well in transductive settings. However, it performs poorly in the more realistic inductive settings where the model has to generalize to links to/from unseen nodes. We find that non-contrastive models tend to overfit to the training graph and use this analysis to propose T-BGRL, a novel non-contrastive framework that incorporates cheap corruptions to improve the generalization ability of the model. This simple modification strongly improves inductive performance in 5/6 of our datasets, with up to a 120% improvement in Hits@50--all with comparable speed to other non-contrastive baselines and up to 14x faster than the best-performing contrastive baseline. Our work imparts interesting findings about non-contrastive learning for link prediction and paves the way for future researchers to further expand upon this area.