Building Multi-turn Intent Classification with LLM-based Labeling

Biancen Xie, Kaiqi Bian, Jai Ranjan Singh Gusain, Manikandarajan Ramanathan, Raj Maragoud


Abstract
Intent classification is essential for customer service routing, connecting customers to the appropriate agents and reducing handling time and operational cost. Developing a real-world multi-turn intent classification system is challenging due to complex intent taxonomies, dynamic intent switching within conversations, and limited labeled training data. To address these challenges, we propose a scalable multi-turn intent classification framework for ecommerce customer service that models intent along multiple dimensions. We introduce LLMbased labeling strategies to annotate real customer transcripts at scale and augment training with LLM-simulated multi-turn dialogues that expand coverage of topic and intent switches, which are rare in existing transcripts. Through extensive experiments, we find that explanationguided labeling with a self-critique step produces the most accurate training labels. Finetuned models built on a RoBERTa backbone outperform zero-shot LLM prompting while achieving substantially lower inference latency. Finally, we show that a hybrid approach that combines the fine-tuned classifier with LLM prompting further improves accuracy over either component alone. Overall, our results provide practical guidance for building and deploying high-accuracy, low-latency, large-scale multi-turn intent classification systems.
Anthology ID:
2026.customnlp4u-1.8
Volume:
Proceedings of the Second Workshop on Customizable NLP: Progress and Challenges in Customizing NLP for a Domain, Application, Group, or Individual (CustomNLP4U)
Month:
July
Year:
2026
Address:
San Diego, California, USA
Editors:
Sheshera Mysore, Sachin Kumar, Vidhisha Balachandran, Shirley Anugrah Hayati, Faeze Brahman, Hanane Nour Moussa, Alireza Salemi
Venues:
CustomNLP4U | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
68–83
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.customnlp4u-1.8/
DOI:
Bibkey:
Cite (ACL):
Biancen Xie, Kaiqi Bian, Jai Ranjan Singh Gusain, Manikandarajan Ramanathan, and Raj Maragoud. 2026. Building Multi-turn Intent Classification with LLM-based Labeling. In Proceedings of the Second Workshop on Customizable NLP: Progress and Challenges in Customizing NLP for a Domain, Application, Group, or Individual (CustomNLP4U), pages 68–83, San Diego, California, USA. Association for Computational Linguistics.
Cite (Informal):
Building Multi-turn Intent Classification with LLM-based Labeling (Xie et al., CustomNLP4U 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.customnlp4u-1.8.pdf