transformer_1376 at SemEval-2026 Task 9: A Multi-Stage Pipeline with Calibrated Ensembles and Lexical Post-Processing for Online Polarization Detection in Bengali

Shuvodwip Saha, Pritha Saha


Abstract
The POLAR @ SemEval-2026 Task 9 deals with the detection of online polarization in a variety of multilingual and multicultural environments. Our team participated in Subtask 1 of the POLAR @ SemEval-2026 Task 9, which mainly deals with binary classification of textual sequences for the detection of polarized stances. In this paper, we proposed a strong classification system for Bengali language based on fine-tuning the BanglaBERT Large model. The methodology used here involves a stratified five-fold cross-validation approach along with a performance-weighted ensemble method, combined with temperature scaling probability calibration and a set of lexical post-processing rules.
Anthology ID:
2026.semeval-1.262
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:
2082–2088
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.262/
DOI:
Bibkey:
Cite (ACL):
Shuvodwip Saha and Pritha Saha. 2026. transformer_1376 at SemEval-2026 Task 9: A Multi-Stage Pipeline with Calibrated Ensembles and Lexical Post-Processing for Online Polarization Detection in Bengali. In Proceedings of the 20th International Workshop on Semantic Evaluation (2026), pages 2082–2088, San Diego, California, USA. Association for Computational Linguistics.
Cite (Informal):
transformer_1376 at SemEval-2026 Task 9: A Multi-Stage Pipeline with Calibrated Ensembles and Lexical Post-Processing for Online Polarization Detection in Bengali (Saha & Saha, SemEval 2026)
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https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.262.pdf