Graph Neural Networks (GNNs) are essential for various graph-based learning tasks. Notably, classical GNN architectures operate under the assumption of homophily, which posits that connected nodes are likely to share similar features. However, this assumption limits the effectiveness of GNNs in handling heterophilic graphs where connected nodes often exhibit dissimilar characteristics. Existing approaches for homophily graphs such as non-local neighbor extension and architectural refinement overlook the rich textual data associated with nodes, which could unlock deeper insights into these heterophilic contexts. With advancements in Large Language Models (LLMs), there is significant promise to enhance GNNs by leveraging the extensive open-world knowledge within LLMs to more effectively interpret and utilize textual data for characterizing heterophilic graphs. In this work, we explore the potential of LLMs for modeling heterophilic graphs and propose a novel two-stage framework: LLM-enhanced edge discriminator and LLM-guided edge reweighting. Specifically, in the first stage, we fine-tune the LLM to better identify homophilic and heterophilic edges based on the textual information of their nodes. In the second stage, we adaptively manage message propagation in GNNs for different edge types based on node features, structures, and heterophilic or homophilic characteristics. To cope with the computational demands when deploying LLMs in practical scenarios, we further explore model distillation techniques to fine-tune smaller, more efficient models that maintain competitive performance. Extensive experiments validate the effectiveness of our framework, demonstrating the feasibility of using LLMs to enhance GNNs for node classification on heterophilic graphs.

本研究解决了传统图神经网络在处理异质图时的局限性，因其过度依赖同质性假设。作者提出了一种新颖的两阶段框架，通过增强边缘鉴别和引导边缘重加权，利用大语言模型来更有效地解读异质图中的文本数据。实验结果表明，该方法能显著提升节点分类的效果，具有重要的实际应用潜力。

探索大语言模型在异质图中的潜力