Domain-Agnostic Neural Topic Modeling with Contextual Token-Level Semantic Graph Representation

Seung-Won Seo, Won Ik Cho, Yongmin Yoo


Abstract
PLM-powered neural topic models depend on general-domain pre-training, leading to degraded topic interpretability on specialized corpora. The root cause is geometric: domain-specific terms unseen during pre-training collapse into an indistinguishable region of the embedding space, and neither domain-specific re-training, word-level graph enrichment, nor parameter-efficient fine-tuning can restructure this space without inheriting the capacity ceiling of the underlying encoder. Our key insight is that a learnable graph layer operating on token-level PLM embeddings can acquire corpus-specific semantic structure that the frozen encoder lacks, because token-level graphs preserve document-local context that word-level representations discard and joint optimization with the topic objective reshapes embedding geometry directly from target-domain evidence. We instantiate this insight as DARTopic, a domain-agnostic framework that constructs token-level semantic graphs from frozen PLM embeddings and jointly trains a GNN encoder with variational topic inference. Across three benchmarks spanning general, biomedical, and legal domains, DARTopic consistently outperforms strong baselines in topic coherence and document clustering without any encoder fine-tuning, while demonstrating robustness to PLM choice and favorable runtime efficiency over fine-tuning-based alternatives.
Anthology ID:
2026.aacl-long.241
Volume:
Proceedings of the 15th International Joint Conference on Natural Language Processing and the 5th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
November
Year:
2026
Address:
Hengqin, China
Editors:
Yue Zhang, Ruifeng Xu, Ayu Purwarianti, Tong Rong, Jun Suzuki
Venues:
AACL | IJCNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
5415–5429
Language:
URL:
https://aclanthology.org/2026.aacl-long.241/
DOI:
Bibkey:
Cite (ACL):
Seung-Won Seo, Won Ik Cho, and Yongmin Yoo. 2026. Domain-Agnostic Neural Topic Modeling with Contextual Token-Level Semantic Graph Representation. In Proceedings of the 15th International Joint Conference on Natural Language Processing and the 5th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics (Volume 1: Long Papers), pages 5415–5429, Hengqin, China. Association for Computational Linguistics.
Cite (Informal):
Domain-Agnostic Neural Topic Modeling with Contextual Token-Level Semantic Graph Representation (Seo et al., AACL-IJCNLP 2026)
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PDF:
https://aclanthology.org/2026.aacl-long.241.pdf