LitSeg: Narrative-Aware Document Segmentation for Literary RAG

Ruikang Zhang, Zhanni Chen, Yiqiao Cai, Qi Su


Abstract
Retrieval-Augmented Generation (RAG) enhances Large Language Models (LLMs) by incorporating external knowledge, particularly for long-tail domains such as literary works. However, the critical step of document segmentation in RAG remains largely underexplored. Existing strategies typically either ignore semantics or overlook the complicated narrative structures of literary works, often resulting in chunks with fragmented plots and unclear references that hinder retrieval and generation performance. To address this, we propose LitSeg, a novel narrative-theory-guided segmentation framework. By employing multi-stage prompting, LitSeg explicitly extracts valid events, clarifies narrative structures, and locates turning points to inform segmentation. To alleviate the computational overhead of multi-stage inference with large-scale models, we further introduce LitSeg-Lite, a lightweight single-pass chunker fine-tuned on LitSeg-generated data via a two-stage training strategy, distilling the complex process into a single inference pass. Extensive experiments demonstrate that compared to baselines, our methods yield high-quality text chunks that are narratologically coherent and self-contained. This improved segmentation quality enhances retrieval accuracy and context relevance, and boosts downstream QA performance. Ablation studies validate the efficacy of narratological guidance and data distillation, and efficiency analysis shows that LitSeg-Lite matches the teacher at a substantially lower inference cost.
Anthology ID:
2026.findings-emnlp.231
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
4862–4892
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.231/
DOI:
Bibkey:
Cite (ACL):
Ruikang Zhang, Zhanni Chen, Yiqiao Cai, and Qi Su. 2026. LitSeg: Narrative-Aware Document Segmentation for Literary RAG. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 4862–4892, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
LitSeg: Narrative-Aware Document Segmentation for Literary RAG (Zhang et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.231.pdf