Similarity-based Neighbor Selection for Graph LLMs
Rui Li Jiwei Li Jiawei Han Guoyin Wang
Text-attributed graphs (TAGs) present unique challenges for direct processing
by Language Learning Models (LLMs), yet their extensive commonsense knowledge
and robust reasoning capabilities offer great promise for node classification
in TAGs. Prior research in this field has grappled with issues such as
over-squashing, heterophily, and ineffective graph information integration,
further compounded by inconsistencies in dataset partitioning and
underutilization of advanced LLMs. To address these challenges, we introduce
Similarity-based Neighbor Selection (SNS). Using SimCSE and advanced neighbor
selection techniques, SNS effectively improves the quality of selected
neighbors, thereby improving graph representation and alleviating issues like
over-squashing and heterophily. Besides, as an inductive and training-free
approach, SNS demonstrates superior generalization and scalability over
traditional GNN methods. Our comprehensive experiments, adhering to standard
dataset partitioning practices, demonstrate that SNS, through simple prompt
interactions with LLMs, consistently outperforms vanilla GNNs and achieves
state-of-the-art results on datasets like PubMed in node classification,
showcasing LLMs' potential in graph structure understanding. Our research
further underscores the significance of graph structure integration in LLM
applications and identifies key factors for their success in node
classification. Code is available at https://github.com/ruili33/SNS.