HP at AraGenre 2026: LLM-Guided Pseudo-Labeling for Hierarchical Arabic Genre Classification with MARBERT

Hoàng Phong Đinh, Thìn Đặng Văn


Abstract
This paper presents the system submitted by team HP for the AraGenre 2026 Shared Task on Hierarchical Definition-Guided Arabic Genre Classification. To address the low-resource constraint of the provided dataset (140 labeled training samples), we propose a two-stage pipeline combining LLM-based pseudo-labeling with supervised fine-tuning. In the first stage, we evaluate several models under a 5-fold cross-validation framework, including Gemini 3.5 Flash Lite (0.9413), Qwen2.5 7B (0.7203), LLaMA 3.1 8B (0.6380), and a multilingual NLI model (0.3099). Based on these results, Gemini 3.5 Flash Lite is selected to generate pseudo-labels for the unlabeled test set using a definition-guided few-shot prompt. In the second stage, MARBERTv2 and ARBERTv2 are fine-tuned on approximately 28,000 pseudo-labeled samples. Our experiments show that MARBERTv2 achieves the best standalone score of 0.7169 Hierarchical Macro F1, outperforming both ARBERTv2 (0.7118) and a soft voting ensemble (0.7165), suggesting that Arabic-specialized pretraining of MARBERTv2 is more effective than model ensembling for this task.
Anthology ID:
2026.arabicnlp-sharedtasks.29
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:
252–256
Language:
URL:
https://aclanthology.org/2026.arabicnlp-sharedtasks.29/
DOI:
Bibkey:
Cite (ACL):
Hoàng Phong Đinh and Thìn Đặng Văn. 2026. HP at AraGenre 2026: LLM-Guided Pseudo-Labeling for Hierarchical Arabic Genre Classification with MARBERT. In Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks, pages 252–256, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
HP at AraGenre 2026: LLM-Guided Pseudo-Labeling for Hierarchical Arabic Genre Classification with MARBERT (Đinh & Văn, ArabicNLP 2026)
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PDF:
https://aclanthology.org/2026.arabicnlp-sharedtasks.29.pdf