Nabra at StanceEval-2026: Exploring Fine-Tuning Strategies for Arabic Stance Detection

Lama Alnashri, Elham Alshanqiti


Abstract
We present Nabra, a system submitted to StanceEval-2026 Track 1 for Arabic stance detection. Our approach fine-tunes MARBERTv2 on the Mawqif-v2 dataset, exploring seven configurations including class weighting, regularization, data augmentation via back-translation, resampling strategies, and zero-shot inference with Qwen2.5-7B. Our best model by the primary metric Favg2 is M1 (Baseline), achieving 0.837 on the development set and 0.6704 on the official blind test set. Error analysis reveals that Favor→Against misclassification accounts for 84.6% of errors, driven by negative sentiment words co-occurring with supportive stances. We find that metric choice (Favg2 vs. Favg3) significantly impacts model selection decisions.
Anthology ID:
2026.arabicnlp-sharedtasks.77
Volume:
Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Muhammad Abdul-Mageed, Tamer Elsayed, Houda Bouamor, Samhaa El-Beltagy, Hend Al-Khalifa, Ahmed Abdelali, AbdelRahim Elmadany, Abdellah El Mekki, Kareem Darwish, Sakhar Alkhereyf, Hamzah Luqman, Salam Khalifa, Samar Magdy, Zaid Alyafeai, Injy Hamed, Wajdi Zaghouani, Imed Zitouni
Venue:
ArabicNLP
SIG:
SIGARAB
Publisher:
Association for Computational Linguistics
Note:
Pages:
613–616
Language:
URL:
https://aclanthology.org/2026.arabicnlp-sharedtasks.77/
DOI:
Bibkey:
Cite (ACL):
Lama Alnashri and Elham Alshanqiti. 2026. Nabra at StanceEval-2026: Exploring Fine-Tuning Strategies for Arabic Stance Detection. In Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks, pages 613–616, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Nabra at StanceEval-2026: Exploring Fine-Tuning Strategies for Arabic Stance Detection (Alnashri & Alshanqiti, ArabicNLP 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.arabicnlp-sharedtasks.77.pdf