CYUT at SemEval-2026 Task 9: Monolingual vs. Multilingual LoRA Tuning for Multicultural and Multievent Polarization Detection

Shih-Hung Wu, Yun-Kuang Liao, Shih-Siang Su, Yi-Min Jian


Abstract
This study addresses SemEval-2026 Task 9 on Detecting Multilingual, Multicultural, and Multievent Online Polarization, exploring the performance differences between monolingual and multilingual LoRA (Low-Rank Adaptation) fine-tuning techniques when processing online polarization phenomena. The research points out that online polarization is not only a language phenomenon, but a complex social language problem highly influenced by cultural contexts and event backgrounds. To address the limitation of existing research that only treats polarization as a binary classification, this study participates in three levels of subtasks: Subtask 1: Polarization Detection, Subtask 2: Polarization Type Classification (e.g., politics, religion), and Subtask 3: Manifestation Identification (analyzing rhetorical strategies that construct polarization, such as stereotypes and dehumanization narratives). This study aims to establish a more contextually grounded and diagnostic model analysis framework to enhance the model’s generalization ability and fairness in cross-lingual environments. By exploring different fine-tuning configurations to build a robust ensemble system, the experimental results show that our approach demonstrates exceptional proficiency in the Chinese domain, securing the 1st place ranking in Subtask 1 (Polarization Detection) for Chinese. Furthermore, we observe that while the monolingual LoRA strategy exhibits strong performance in specific languages like Chinese, integrating it with multilingual LoRA models via ensembling provides the diverse features crucial for identifying complex cross-cultural rhetoric.
Anthology ID:
2026.semeval-1.209
Volume:
Proceedings of the 20th International Workshop on Semantic Evaluation (2026)
Month:
July
Year:
2026
Address:
San Diego, California, USA
Editors:
Ekaterina Kochmar, Debanjan Ghosh, Kai North, Mamoru Komachi
Venues:
SemEval | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
1621–1631
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.209/
DOI:
Bibkey:
Cite (ACL):
Shih-Hung Wu, Yun-Kuang Liao, Shih-Siang Su, and Yi-Min Jian. 2026. CYUT at SemEval-2026 Task 9: Monolingual vs. Multilingual LoRA Tuning for Multicultural and Multievent Polarization Detection. In Proceedings of the 20th International Workshop on Semantic Evaluation (2026), pages 1621–1631, San Diego, California, USA. Association for Computational Linguistics.
Cite (Informal):
CYUT at SemEval-2026 Task 9: Monolingual vs. Multilingual LoRA Tuning for Multicultural and Multievent Polarization Detection (Wu et al., SemEval 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.209.pdf