Graph Self-Supervised Learning Via Learnable View Augmentation for Recommender System

In the field of recommender systems, graph neural networks (GNNs) have been extensively applied to collaborative filtering to generate personalized recommendations for users. To solve the problem of lack of observed data and contrasting interactions during representation learning, graph contrastive learning as an effective self-supervised learning (SSL) technique is presented to obtain augmented user and item representations. Nevertheless, most self-supervised approaches to generate recommendation either disrupt the graph structure or node embeddings through random augmentations or introduce augmented SSL information from biased data through heuristic methods. To overcome these challenges, we propose a learnable view augmentation model for collaborative filtering (LACF). Specifically, our framework embeds parameterized learnable view generators layer by layer into the automatic augmentation strategy, thus dynamically optimizing the adaptive augmented views of users and items through the backpropagation of weight gradients. In addition, LACF introduces a multiscale learning strategy that guides the view generator with layer-wise aware optimization and graph-level adaptive augmentation, enabling joint learning of representations with topological heterogeneity and semantic similarity from integrated viewpoint, achieving superior view augmentation. Extensive experiments on realworld datasets demonstrate that our LACF outperforms state-of-the-art baselines. In-depth analysis confirms the advantages of LACF in resistance against noise disturbances, alleviating data sparsity, and improving training efficiency.