Node Role-Guided LLMs for Dynamic Graph Clustering
Organizations: The University of Tokyo Tokyo, Japan · RIKEN Sendai, Japan
Abstract
Dynamic graph clustering aims to detect and track time-varying clusters in dynamic graphs, revealing how complex real-world systems evolve over time. However, existing methods are predominantly black-box models. They lack interpretability in their clustering decisions and fail to provide semantic explanations of why clusters form or how they evolve, severely limiting their use in safety-critical domains such as healthcare or transportation. To address these limitations, we propose an end-to-end interpretable framework that maps continuous graph embeddings into discrete semantic concepts through learnable prototypes. Specifically, we first decompose node representations into orthogonal role and clustering subspaces, so that nodes with similar roles (e.g., hubs, bridges) but different cluster affiliations can be properly distinguished. We then introduce five node role prototypes (Leader, Contributor, Wanderer, Connector, Newcomer) in the role subspace as semantic anchors, transforming continuous embeddings into discrete concepts to facilitate LLM understanding of node roles within communities. Finally, we design a hierarchical LLM reasoning mechanism to generate both clustering results and natural language explanations, while providing consistency feedback as weak supervision to refine node representations. Experimental results on four synthetic and six real-world benchmarks demonstrate the effectiveness, interpretability, and robustness of DyG-RoLLM. Code is available at https://github.com/Clearloveyuan/DyG-RoLLM.
Figures & tables
| Dynamic Graphs | # of Nodes | # of Edges | # of Snapshots |
| Birth-Death (BD) | 30K & 100K | 12M & 24M | 10 & 20 |
| Expand-Contract (EC) | 30K & 100K | 13M & 26M | 10 & 20 |
| Disappear-Reappear (DR) | 30K & 100K | 13M & 28M | 10 & 20 |
| Merge-Split (MS) | 30K & 100K | 14M & 29M | 10 & 20 |
| Wikipedia | 8,400 | 162,000 | 5 |
| Dublin | 11,000 | 415,900 | 5 |
| Methods | BD-30K | EC-30K | BD-100K | DR-100K | MS-100K | Wikipedia | Dublin | arXiv | SO | Flickr | Youtube | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| NMI | NF1 | NMI | NF1 | NMI | NF1 | NMI | NF1 | NMI | NF1 | NMI | NF1 | NMI | NF1 | NMI | NF1 | NMI | NF1 | NMI | NF1 | NMI | NF1 | |||
| NN-based | node2vec ( Grover and Leskovec, 2016 ) | 93.8 | 85.8 | 93.2 | 83.6 | 90.3 | 84.2 | 91.2 | 85.6 | 89.0 | 78.2 | 33.5 | 10.2 | 50.3 | 23.2 | 44.3 | 26.8 | 40.3 | 23.3 | 42.4 | 25.5 | 42.8 | 24.5 | |
| RNNGCN ( Yao and Joe-Wong, 2021 ) | 96.6 | 84.5 | 95.9 | 85.1 | 90.8 | 84.9 | 92.1 | 84.3 | 91.2 | 80.9 | 40.3 | 22.5 | 52.2 | 31.6 | 45.4 | 26.2 | 40.8 | 23.8 | 48.5 | 30.2 | 47.6 | 32.3 | ||
| SepNE ( Li et al., 2019 ) | 92.5 | 89.4 | 92.1 | 81.8 | 89.1 | 82.2 | 89.0 | 81.1 | 89.2 | 78.6 | 31.4 | 9.8 | 49.2 | 21.0 | 42.8 | 25.8 | 39.2 | 22.1 | 40.3 | 22.4 | 39.5 | 21.0 | ||
| ROLAND ( You et al., 2022 ) | 95.5 | 83.2 | 94.1 | 83.8 | 92.8 | 85.1 | 93.3 | 85.8 | 92.8 | 81.6 | 42.2 | 22.3 | 53.6 | 31.6 | 46.8 | 27.6 | 44.8 | 29.2 | 47.5 | 31.4 | 48.4 | 33.2 | ||
| TGC ( Liu et al., 2024a ) | 95.3 | 83.0 | 93.8 | 83.6 | 92.0 | 84.5 | 92.8 | 85.4 | 91.5 | 81.2 | 41.3 | 22.3 | 52.8 | 31.3 | 45.8 | 26.8 | 44.6 | 29.0 | 47.8 | 31.6 | 47.9 | 32.6 | ||
| Method | Wikipedia | Dublin | SO | |||
|---|---|---|---|---|---|---|
| RCS↑ | EFS↑ | RCS↑ | EFS↑ | RCS↑ | EFS↑ | |
| ComGPT (+CoT) | 0.69 | 0.58 | 0.64 | 0.55 | 0.71 | 0.60 |
| CommLLM (+CoT) | 0.62 | 0.51 | 0.58 | 0.47 | 0.65 | 0.53 |
| DyG-RoLLM (w/o Role) | 0.75 | 0.66 | 0.68 | 0.68 | 0.83 | 0.82 |
| DyG-RoLLM (w/o CoT) | 0.85 | 0.64 | 0.82 | 0.66 | 0.87 | 0.68 |
| DyG-RoLLM | 0.88 | 0.89 | 0.88 | 0.90 | 0.92 | 0.91 |
| Method | Clarity | Soundness | Complete | Trust | Action |
|---|---|---|---|---|---|
| ComGPT (+CoT) | 3.2 | 2.8 | 2.6 | 2.9 | 2.5 |
| CommLLM (+CoT) | 2.9 | 2.5 | 2.4 | 2.6 | 2.3 |
| DyG-RoLLM (w/o Role) | 3.5 | 3.3 | 3.1 | 3.4 | 3.2 |
| DyG-RoLLM (w/o CoT) | 3.8 | 3.6 | 3.4 | 3.7 | 3.5 |
| DyG-RoLLM (full) | 4.4 | 4.5 | 4.3 | 4.6 | 4.2 |
| Methods | Wikipedia | arXiv | |||
| NMI↑ | NF1↑ | NMI↑ | NF1↑ | ||
| Remove | w/o Orthogonal Subspace | 42.2 | 22.4 | 43.5 | 15.8 |
| w/o Clustering loss Eq.( 6 ) | 50.3 | 25.6 | 51.6 | 30.0 | |
| w/o Temporal loss Eq.( 7 ) | 51.0 | 26.3 | 52.5 | 31.7 | |
| w/o Contrastive loss Eq.( 11 ) | 50.6 | 25.7 | 51.7 | 30.1 | |
| w/o Consistent loss Eq.( 16 ) | 50.0 | 25.1 | 51.2 | 29.7 | |
Appendix figures & tables1 asset
Supplementary material from the paper’s appendix.
Appendix
| Prototype ( ) | Centrality ( ) | Local Structure ( ) | Temporal ( ) | ||||
|---|---|---|---|---|---|---|---|
| Degree | Betweenness | Closeness | Clustering Coeff. | Intra-Density | Volatility | Stability | |
| Community Leader ( ) | |||||||
| Active Member ( ) | |||||||
| Peripheral Member ( ) | |||||||
| Bridge Node ( ) | |||||||
| Newcomer/Evolver ( ) | |||||||
Graph Clustering
Graph clustering groups network nodes by connectivity, attributes, or shared roles to reveal communities and other mesoscale structure.
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