LCTeam at SemEval-2025 Task 3: Multilingual Detection of Hallucinations and Overgeneration Mistakes Using XLM-RoBERTa

Araya Hailemariam, Jose Maldonado Rodriguez, Ezgi Başar, Roman Kovalev, Hanna Shcharbakova


Abstract
In recent years, the tendency of large language models to produce hallucinations has become an object of academic interest. Hallucinated or overgenerated outputs created by LLMs contain factual inaccuracies which can potentially invalidate textual coherence. The Mu-SHROOM shared task sets the goal of developing strategies for detecting hallucinated parts of LLM outputs in a multilingual context. We present an approach applicable across multiple languages, which incorporates the alignment of tokens and hard labels, as well as training a multi-lingual XLM-RoBERTa model. With this approach we managed to achieve 2nd in Chinese and top-10 positions in 7 other language tracks of the competition.
Anthology ID:
2025.semeval-1.176
Volume:
Proceedings of the 19th International Workshop on Semantic Evaluation (SemEval-2025)
Month:
July
Year:
2025
Address:
Vienna, Austria
Editors:
Sara Rosenthal, Aiala Rosá, Debanjan Ghosh, Marcos Zampieri
Venues:
SemEval | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
1325–1331
Language:
URL:
https://preview.aclanthology.org/corrections-2025-08/2025.semeval-1.176/
DOI:
Bibkey:
Cite (ACL):
Araya Hailemariam, Jose Maldonado Rodriguez, Ezgi Başar, Roman Kovalev, and Hanna Shcharbakova. 2025. LCTeam at SemEval-2025 Task 3: Multilingual Detection of Hallucinations and Overgeneration Mistakes Using XLM-RoBERTa. In Proceedings of the 19th International Workshop on Semantic Evaluation (SemEval-2025), pages 1325–1331, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
LCTeam at SemEval-2025 Task 3: Multilingual Detection of Hallucinations and Overgeneration Mistakes Using XLM-RoBERTa (Hailemariam et al., SemEval 2025)
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PDF:
https://preview.aclanthology.org/corrections-2025-08/2025.semeval-1.176.pdf