Graph neural networks (GNNs) have demonstrated remarkable effectiveness in various graph representation learning tasks. However, most of existing methods achieve the information extraction by the simple fusion of local and global information, which is a coarse-grained and static way. This may hinder the establishment of a dynamic and collaborative interaction between global and local information, which is crucial for comprehensively understanding graph data. To address this challenge, we propose a novel framework called comprehensive graph representation learning (ComGRL). ComGRL integrates local information into global information to derive powerful representations. It achieves this by implicitly smoothing local information through flexible graph contrastive learning, ensuring reliable representations for subsequent global exploration. Then ComGRL transfers the locally derived representations to a multihead self-attention module, enhancing their discriminative ability by uncovering diverse and rich global correlations. To achieve dynamic transformation between global and local information under self-supervision with pseudo-labels, ComGRL employs a triple sampling strategy to construct mixed node pairs and applies reliable Mixup augmentation across attributes and structure for the main frameworks. This approach broadens the receptive field and facilitates coordination between local and global representation learning, enabling them to reinforce each other. Experimental results across six widely used graph datasets demonstrate that ComGRL achieves excellent performance in node classification tasks. The code could be available athttps://github.com/JinluWang1002/ComGRL.

Due to its powerful capability of self-supervised representation learning and clustering, contrastive attributed graph clustering (CAGC) has achieved great success, which mainly depends on effective data augmentation and contrastive objective setting. However, most CAGC methods utilize edges as auxiliary information to obtain node-level embedding representation and only focus on node-level embedding augmentation. This approach overlooks edge-level embedding augmentation and the interactions between node-level and edge-level embedding augmentations across various granularity. Moreover, they often treat all contrastive sample pairs equally, neglecting the significant differences between hard and easy positive-negative sample pairs, which ultimately limits their discriminative capability. To tackle these issues, a novel robust attributed graph clustering (RAGC), incorporating hybrid-collaborative augmentation (HCA) and contrastive sample adaptive-differential awareness (CSADA), is proposed. First, node-level and edge-level embedding representations and augmentations are simultaneously executed to establish a more comprehensive similarity measurement criterion for subsequent contrastive learning. In turn, the discriminative similarity further consciously guides edge augmentation. Second, by leveraging pseudo-label information with high confidence, a CSADA strategy is elaborately designed, which adaptively identifies all contrastive sample pairs and differentially treats them by an innovative weight modulation function. The HCA and CSADA modules mutually reinforce each other in a beneficent cycle, thereby enhancing discriminability in representation learning. Comprehensive graph clustering evaluations over six benchmark datasets demonstrate the effectiveness of the proposed RAGC against several state-of-the-art CAGC methods. The code of RAGC could be available at https://github.com/TianxiangZhao0474/RAGC.git.

Graph neural networks (GNNs) exhibit a robust capability for representation learning on graphs with complex structures, demonstrating superior performance across various applications. Most existing GNNs utilize graph convolution operations that integrate both attribute and structural information through coupled way. And these GNNs, from an optimization perspective, seek to learn a consensus and compromised embedding representation that balances attribute and graph information, selectively exploring and retaining valid information in essence. To obtain a more comprehensive embedding representation, a novel GNN framework, dubbed Decoupled Graph Neural Networks (DGNN), is introduced. DGNN separately explores distinctive embedding representations from the attribute and graph spaces by decoupled terms. Considering that the semantic graph, derived from attribute feature space, contains different node connection information and provides enhancement for the topological graph, both topological and semantic graphs are integrated by DGNN for powerful embedding representation learning. Further, structural consistency between the attribute embedding and the graph embedding is promoted to effectively eliminate redundant information and establish soft connection. This process involves facilitating factor sharing for adjacency matrices reconstruction, which aims at exploring consensus and high-level correlations. Finally, a more powerful and comprehensive representation is achieved through the concatenation of these embeddings. Experimental results conducted on several graph benchmark datasets demonstrate its superiority in node classification tasks.