Nasaq at AraGenre 2026: Definition-Guided Approaches for Hierarchical Arabic Genre Classification

Samar Ahmad, Abdullah I. Alharbi, Shahad Altamimi, Yahya Assiri, Morooj Alrajhi


Abstract
We describe SynAnchor, Nasaq’s definition-guided system for AraGenre 2026. The task requires hierarchical Arabic genre classification under disjoint specific-genre inventories across training, development, and test, making generalization to unseen genres a central challenge. SynAnchor addresses this setting by generating Arabic anchor texts from genre definitions using GPT-4o and embedding them with BGE-M3 for similarity-based retrieval. High-confidence cases are classified directly, while ambiguous inputs are selectively adjudicated by GPT-5 among the three highest-ranked candidate genres. On the official test set of 27,972 texts spanning 74 unseen specific genres, SynAnchor achieves a Hierarchical Macro-F1 of 0.6006 on Codabench, compared with 0.2472 for the organizers’ definition-embedding baseline (approximately 2.4). Approximately 25% of test instances are resolved using retrieval alone, without LLM adjudication. The results suggest that combining definition-guided Arabic anchor synthesis with selective LLM reasoning can support hierarchical genre classification under changing label inventories.
Anthology ID:
2026.arabicnlp-sharedtasks.35
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:
281–287
Language:
URL:
https://aclanthology.org/2026.arabicnlp-sharedtasks.35/
DOI:
Bibkey:
Cite (ACL):
Samar Ahmad, Abdullah I. Alharbi, Shahad Altamimi, Yahya Assiri, and Morooj Alrajhi. 2026. Nasaq at AraGenre 2026: Definition-Guided Approaches for Hierarchical Arabic Genre Classification. In Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks, pages 281–287, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Nasaq at AraGenre 2026: Definition-Guided Approaches for Hierarchical Arabic Genre Classification (Ahmad et al., ArabicNLP 2026)
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PDF:
https://aclanthology.org/2026.arabicnlp-sharedtasks.35.pdf