phonghoang at StanceEval-2026: A Two-Stage Framework for Arabic Stance Detection via Multi-Task Regularization and LLM-Guided Data Augmentation

Hoàng Phong Đinh, Thìn Đặng Văn


Abstract
This paper describes the system submitted by the phonghoang team for Track 1 (Seen Tar- gets) of the StanceEval-2026 shared task on Arabic stance detection, where models are trained on provided targets and evaluated on a related target within the same thematic do- main. We propose a two-stage framework to address this within-domain target shift. In the first stage, we fine-tune a Multi-Task MAR- BERT model that jointly learns stance, senti- ment, and sarcasm, further regularized with R- Drop and Stochastic Weight Averaging (SWA), achieving Favg2 of 0.8561 on the development set. In the second stage, we adapt to the test target (“Women Driving”) by combining con- trastive few-shot pseudo-labeling via a Large Language Model, fusion with an external Ara- bic stance dataset, and high-confidence samples filtered from a thematically related training tar- get. The resulting augmented training set is used to adapt our optimal Stage 1 architecture, achieving an official Favg2 of 0.8431 on the test set.
Anthology ID:
2026.arabicnlp-sharedtasks.73
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:
568–572
Language:
URL:
https://aclanthology.org/2026.arabicnlp-sharedtasks.73/
DOI:
Bibkey:
Cite (ACL):
Hoàng Phong Đinh and Thìn Đặng Văn. 2026. phonghoang at StanceEval-2026: A Two-Stage Framework for Arabic Stance Detection via Multi-Task Regularization and LLM-Guided Data Augmentation. In Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks, pages 568–572, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
phonghoang at StanceEval-2026: A Two-Stage Framework for Arabic Stance Detection via Multi-Task Regularization and LLM-Guided Data Augmentation (Đinh & Văn, ArabicNLP 2026)
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PDF:
https://aclanthology.org/2026.arabicnlp-sharedtasks.73.pdf