U4RASD at StanceEval 2026: Fine-Tuning, Prompting, and Ensembling for Unseen-Target Arabic Stance Detection

Giovanni Khadra, Mohamad Chhaytle, Nancy Hamdan, Fadi Zaraket


Abstract
This paper describes our system for StanceEval 2026 Track 2, which requires predicting stance toward targets not seen during training. We explored fine-tuning different Arabic BERT encoder models, using class weighting techniques, incorporating auxiliary sentiment and sarcasm tasks in sequential and parallel multi-task setups, and focal and margin-based contrastive losses. We also tried zero-shot and few-shot prompting, self-consistency with escalation, LoRA fine-tuning, and an ensemble approach. Our best-performing submission on the official blind test set was a training-free few-shot prompting approach using Gemini 2.5 Flash with an extended prompt, achieving an Favg2 of 87.41 and an Favg3 of 76.94, and ranking 8th out of 13 teams. This result shows that a simpler, training-free prompting approach can generalize to unseen targets more effectively than fine-tuned and ensemble systems.
Anthology ID:
2026.arabicnlp-sharedtasks.79
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:
625–635
Language:
URL:
https://aclanthology.org/2026.arabicnlp-sharedtasks.79/
DOI:
Bibkey:
Cite (ACL):
Giovanni Khadra, Mohamad Chhaytle, Nancy Hamdan, and Fadi Zaraket. 2026. U4RASD at StanceEval 2026: Fine-Tuning, Prompting, and Ensembling for Unseen-Target Arabic Stance Detection. In Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks, pages 625–635, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
U4RASD at StanceEval 2026: Fine-Tuning, Prompting, and Ensembling for Unseen-Target Arabic Stance Detection (Khadra et al., ArabicNLP 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.arabicnlp-sharedtasks.79.pdf