UIT-Polar at SemEval-2026 Task 9 Detecting Multilingual, Multicultural and Multievent Online Polarization

Hoàn Trần


Abstract
We present a two-stage hybrid system forSemEval-2026 Task 9 on multilingual and mul-tievent online polarization detection. The firststage employs DeBERTa for high-recall binaryfiltering to mitigate severe class imbalance. Thesecond stage leverages Mistral for fine-grainedpolarization classification, enabling improvedsemantic reasoning over candidate instances.This coarse-to-fine design enhances robustnessand efficiency while preserving minority-classperformance. Our system achieves Top-5 results on the English test set, demonstratingthe effectiveness of integrating encoder-basedscreening with LLM-based refinement.
Anthology ID:
2026.semeval-1.19
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:
127–132
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.19/
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Bibkey:
Cite (ACL):
Hoàn Trần. 2026. UIT-Polar at SemEval-2026 Task 9 Detecting Multilingual, Multicultural and Multievent Online Polarization. In Proceedings of the 20th International Workshop on Semantic Evaluation (2026), pages 127–132, San Diego, California, USA. Association for Computational Linguistics.
Cite (Informal):
UIT-Polar at SemEval-2026 Task 9 Detecting Multilingual, Multicultural and Multievent Online Polarization (Trần, SemEval 2026)
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https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.19.pdf