Referential ambiguity and clarification requests: comparing human and LLM behaviour

Chris Madge, Matthew Purver, Massimo Poesio


Abstract
In this work we examine LLMs’ ability to ask clarification questions in task-oriented dialogues that follow the asynchronous instruction-giver/instruction-follower format. We present a new corpus that combines two existing annotations of the Minecraft Dialogue Corpus — one for reference and ambiguity in reference, and one for SDRT including clarifications — into a single common format providing the necessary information to experiment with clarifications and their relation to ambiguity. With this corpus we compare LLM actions with original human-generated clarification questions, examining how both humans and LLMs act in the case of ambiguity. We find that there is only a weak link between ambiguity and humans producing clarification questions in these dialogues, and low correlation between humans and LLMs. Humans hardly ever produce clarification questions for referential ambiguity, but often do so for task-based uncertainty. Conversely, LLMs produce more clarification questions for referential ambiguity, but less so for task uncertainty. We question if LLMs’ ability to ask clarification questions is predicated on their recent ability to simulate reasoning, and test this with different reasoning approaches, finding that reasoning does appear to increase question frequency and relevancy.
Anthology ID:
2025.crac-1.1
Volume:
Proceedings of the Eighth Workshop on Computational Models of Reference, Anaphora and Coreference
Month:
November
Year:
2025
Address:
Suzhou, China
Editors:
Maciej Ogrodniczuk, Michal Novak, Massimo Poesio, Sameer Pradhan, Vincent Ng
Venue:
CRAC
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
1–11
Language:
URL:
https://aclanthology.org/2025.crac-1.1/
DOI:
Bibkey:
Cite (ACL):
Chris Madge, Matthew Purver, and Massimo Poesio. 2025. Referential ambiguity and clarification requests: comparing human and LLM behaviour. In Proceedings of the Eighth Workshop on Computational Models of Reference, Anaphora and Coreference, pages 1–11, Suzhou, China. Association for Computational Linguistics.
Cite (Informal):
Referential ambiguity and clarification requests: comparing human and LLM behaviour (Madge et al., CRAC 2025)
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PDF:
https://aclanthology.org/2025.crac-1.1.pdf