Joshualee2 at SemEval-2026 Task 9: Cross-Lingual Transformer-Based Polarization Detection
Summary
Joshualee2's system, developed for SemEval-2026 Task 9 (POLAR Subtask 1), addresses multilingual polarization detection across 22 languages. The task requires binary sequence classification to identify polarized discourse in text. To manage the dataset's multilingual and resource-imbalanced nature, the system fine-tunes XLM-R, a pre-trained multilingual transformer encoder. This fine-tuning employs a language-aware sampling strategy, integrating all training data into a single multilingual corpus. The system achieved a macro-F1 of 0.781 and an average accuracy of 0.823 on the official test set. Notably, it demonstrated strong performance in low-resource languages, although some class imbalance issues persist.
Key takeaway
For NLP Engineers building cross-lingual text classification systems, especially with resource-imbalanced datasets, consider fine-tuning multilingual transformer encoders like XLM-R. Your approach should incorporate a language-aware sampling strategy to unify diverse language data, which can significantly improve performance in low-resource languages. This method achieved a macro-F1 of 0.781, demonstrating its effectiveness for detecting polarized discourse across 22 languages.
Key insights
Fine-tuning XLM-R with language-aware sampling effectively detects cross-lingual polarization, showing strong performance in low-resource languages.
Principles
- Multilingual transformers unify diverse language data.
- Language-aware sampling mitigates resource imbalance.
- Fine-tuning improves cross-lingual text classification.
Method
Fine-tune the XLM-R multilingual transformer encoder using a language-aware sampling strategy. This combines all available training data into a unified multilingual corpus for binary sequence classification.
In practice
- Apply XLM-R for cross-lingual text tasks.
- Implement language-aware sampling for imbalanced data.
- Unify multilingual corpora for training efficiency.
Topics
- Cross-Lingual NLP
- Polarization Detection
- XLM-R
- Transformer Encoders
- Language-Aware Sampling
- SemEval-2026
Best for: Research Scientist, AI Scientist, Machine Learning Engineer, NLP Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by Paper Index on ACL Anthology.