IReL_IIT(BHU) at SemEval-2026 Task 9: Detecting Multilingual, Multicultural and Multievent Online Polarization
Paper · 2026 · Soumadip Majumder, Arjun Mukherjee, Krishna Tewari et al.
Summary
This system paper reports the IReL_IIT(BHU) entry for the Chinese track of SemEval-2026 Task 9, which covers online polarization. The team entered all three subtasks: binary detection of polarized text, multi-label classification of polarization type, and multi-label identification of how polarization manifests. They argue that earlier systems handled these tasks with separate pipelines, used fixed thresholds, and ensembled in an ad hoc way. Their alternative is one shared workflow. Chinese encoders (Erlangshen-DeBERTa and MacBERT) are fine-tuned with stratified 5-fold cross-validation. The out-of-fold (OOF) probabilities then serve two purposes: calibrating decision thresholds and choosing ensemble weights. Preprocessing on the official shared-task data was kept deliberately light. A single DeBERTa model performed best on the binary task, while weighted DeBERTa-heavy ensembles helped on the multi-label subtasks. Official test Macro-F1 was 0.9081, 0.7962 and 0.6484. The authors conclude that careful calibration and validation design matter. They also note that manifestation labels, which depend on implicit, context-dependent cues, remain hard to predict.
Key points
- Backbones: IDEA-CCNL/Erlangshen-DeBERTa-v2-320M-Chinese was the strongest single model, and hfl/chinese-macbert-large added complementary signal. For Subtask 1, mDeBERTa-v3 and XLM-R were also tried.
- Final configurations:
- Subtask 1: a single DeBERTa model with an OOF-tuned threshold slightly under 0.5.
- Subtask 2: a 0.6/0.4 DeBERTa/MacBERT ensemble over 5 labels.
- Subtask 3: a 0.9/0.1 ensemble over 6 labels.
- Both multi-label subtasks used per-label thresholds and BCEWithLogitsLoss with per-label pos_weight.
- Training: AdamW with a learning rate of about 1.5e-5, FP16, early stopping with patience 2, and seed 42, run on an RTX 4060 laptop GPU. Maximum sequence length was 128, 192 and 256 for Subtasks 1–3.
- Test results (Macro-F1 / rank):
- Subtask 1: 0.9081 (10th)
- Subtask 2: 0.7962 (8th)
- Subtask 3: 0.6484 (7th)
- Generalization gaps:
- Subtask 3 fell from 0.7136 in the development phase to 0.6484 on test.
- Per-label ensemble weighting raised OOF scores but overfit.
- The hardest labels were "other" among polarization types and "lack of empathy" among manifestations.
Institutions
Fields, topics and concepts
📚 Shelves 4The field of science this work belongs to (OpenAlex fields).Computer Science · 18,614 worksArtificial Intelligence · 17,965 worksSocial Sciences · 1,954 worksSociology and Political Science · 626 works
🧭 Topics 1Research subjects and languages the work is about.Multilingual & cross-lingual NLP · 882 works
Cite
Cite as Soumadip Majumder, Arjun Mukherjee, Krishna Tewari, Sanjaya Lenka and Sukomal Pal. 2026. IReL_IIT(BHU) at SemEval-2026 Task 9: Detecting Multilingual, Multicultural and Multievent Online Polarization. Proceedings of the 20th International Workshop on Semantic Evaluation (2026).
@inproceedings{majumder2026irel,
title = {{IReL\_IIT(BHU) at SemEval-2026 Task 9: Detecting Multilingual, Multicultural and Multievent Online Polarization}},
author = {Soumadip Majumder, Arjun Mukherjee, Krishna Tewari, Sanjaya Lenka and Sukomal Pal},
booktitle = {Proceedings of the 20th International Workshop on Semantic Evaluation (2026)},
year = {2026},
doi = {10.18653/v1/2026.semeval-1.297},
url = {https://doi.org/10.18653/v1/2026.semeval-1.297}
}References
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