Efficient Out-of-Scope Detection in Dialogue Systems via Uncertainty-Driven LLM Routing
Álvaro Zaera, Diana Nicoleta Popa, Ivan Sekulic, Paolo Rosso
Abstract
Out-of-scope (OOS) intent detection is a critical challenge in task-oriented dialogue systems (TODS), as it ensures robustness to unseen and ambiguous queries. In this work, we propose a novel but simple modular framework that combines uncertainty modeling with fine-tuned large language models (LLMs) for efficient and accurate OOS detection. The first step applies uncertainty estimation to the output of an in-scope intent detection classifier, which is currently deployed in a real-world TODS handling tens of thousands of user interactions daily. The second step then leverages an emerging LLM-based approach, where a fine-tuned LLM is triggered to make a final decision on instances with high uncertainty.Unlike prior approaches, our method effectively balances computational efficiency and performance, combining traditional approaches with LLMs and yielding state-of-the-art results on key OOS detection benchmarks, including real-world OOS data acquired from a deployed TODS.- Anthology ID:
- 2025.acl-industry.25
- Volume:
- Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 6: Industry Track)
- Month:
- July
- Year:
- 2025
- Address:
- Vienna, Austria
- Editors:
- Georg Rehm, Yunyao Li
- Venue:
- ACL
- SIG:
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 328–335
- Language:
- URL:
- https://preview.aclanthology.org/landing_page/2025.acl-industry.25/
- DOI:
- Cite (ACL):
- Álvaro Zaera, Diana Nicoleta Popa, Ivan Sekulic, and Paolo Rosso. 2025. Efficient Out-of-Scope Detection in Dialogue Systems via Uncertainty-Driven LLM Routing. In Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 6: Industry Track), pages 328–335, Vienna, Austria. Association for Computational Linguistics.
- Cite (Informal):
- Efficient Out-of-Scope Detection in Dialogue Systems via Uncertainty-Driven LLM Routing (Zaera et al., ACL 2025)
- PDF:
- https://preview.aclanthology.org/landing_page/2025.acl-industry.25.pdf