Graph-tree Fusion Model with Bidirectional Information Propagation for Long Document Classification

Sudipta Singha Roy, Xindi Wang, Robert Mercer, Frank Rudzicz


Abstract
Long document classification presents challenges in capturing both local and global dependencies due to their extensive content and complex structure. Existing methods often struggle with token limits and fail to adequately model hierarchical relationships within documents. To address these constraints, we propose a novel model leveraging a graph-tree structure. Our approach integrates syntax trees for sentence encodings and document graphs for document encodings, which capture fine-grained syntactic relationships and broader document contexts, respectively. We use Tree Transformers to generate sentence encodings, while a graph attention network models inter- and intra-sentence dependencies. During training, we implement bidirectional information propagation from word-to-sentence-to-document and vice versa, which enriches the contextual representation. Our proposed method enables a comprehensive understanding of content at all hierarchical levels and effectively handles arbitrarily long contexts without token limit constraints. Experimental results demonstrate the effectiveness of our approach in all types of long document classification tasks.
Anthology ID:
2024.findings-emnlp.257
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2024
Month:
November
Year:
2024
Address:
Miami, Florida, USA
Editors:
Yaser Al-Onaizan, Mohit Bansal, Yun-Nung Chen
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
4460–4470
Language:
URL:
https://aclanthology.org/2024.findings-emnlp.257/
DOI:
10.18653/v1/2024.findings-emnlp.257
Bibkey:
Cite (ACL):
Sudipta Singha Roy, Xindi Wang, Robert Mercer, and Frank Rudzicz. 2024. Graph-tree Fusion Model with Bidirectional Information Propagation for Long Document Classification. In Findings of the Association for Computational Linguistics: EMNLP 2024, pages 4460–4470, Miami, Florida, USA. Association for Computational Linguistics.
Cite (Informal):
Graph-tree Fusion Model with Bidirectional Information Propagation for Long Document Classification (Singha Roy et al., Findings 2024)
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PDF:
https://aclanthology.org/2024.findings-emnlp.257.pdf