How to Make LMs Strong Node Classifiers?

Zhe Xu, Kaveh Hassani, Si Zhang, Hanqing Zeng, Michihiro Yasunaga, Limei Wang, Dongqi Fu, Ning Yao, Bo Long, Hanghang Tong

Main figure for How to Make LMs Strong Node Classifiers?

Abstract

Language Models (LMs) are increasingly challenging the dominance of domain-specific models, such as Graph Neural Networks (GNNs) and Graph Transformers (GTs), in graph learning tasks. Following this trend, we propose a novel approach that empowers off-the-shelf LMs to achieve performance comparable to state-of-the-art (SOTA) GNNs on node classification tasks, without any architectural modification. By preserving the LM's original architecture, our approach retains a key benefit of LM instruction tuning: the ability to jointly train on diverse datasets, fostering greater flexibility and efficiency. To achieve this, we introduce two key augmentation strategies: (1) enriching LMs' input using topological and semantic retrieval methods, providing richer contextual information, and (2) guiding the LMs' classification process through a lightweight GNN classifier that effectively prunes class candidates. Experiments on real-world datasets show that backbone Flan-T5 LMs equipped with these augmentation strategies outperform SOTA text-output node classifiers and are comparable to top-performing vector-output node classifiers. By bridging the gap between specialized node classifiers and general LMs, this work paves the way for more versatile and widely applicable graph learning models. We will open-source the code upon publication.

Proposed method: AuGLM (T5-large)

Benchmark Results

Tested on 1 dataset 2 baseline values reported too low

Tables show presented results in global context (best 3 papers + GCN + MLP).

OGB

#ModelAccuracy ↑Paper
1
Jacobi
0.8968
2
GPR
0.8953
3
LEMP4HG
0.8939
4
SAGE
0.8933
6
GCN
actual #6 vs paper #250 244 places worse
0.8868
best reported
actual #6 vs paper #250 244 places worse
paper 0.7564 ±0.0021
80
AuGLM (T5-large)
0.8290 ±0.0010
This paper
83
GraphSAGE
actual #83 vs paper #242 159 places worse
0.8287
best reported
actual #83 vs paper #242 159 places worse
paper 0.7604 ±0.0025
91
TAPE + RevGAT
0.8234 ±0.0036
This paper
110
GraphICL
0.8148
This paper
160
GraphPrompter
0.7954
This paper
320
GIANT + RevGAT
0.7189 ±0.0030
This paper
338
GIANT + GCN
0.6977 ±0.0042
This paper
351
MLP
0.6605 ±0.0020
SOTA performance (not significantly different from the best) Proposed method (this paper) Baseline / comparison (this paper) Global context (other papers) Best at pub — reported result worse than the best known when published (best reported in green)