NAMAA Community at AraSeg Shared Task 2026: Model Diversity, Conditional Decoding, and Missing Punctuation in Arabic Sentence Segmentation

Muhammed Ragab, Khloud Al Jallad, Karim Elsayed, Omer Nacar


Abstract
We present NAMAA Community’s systems for the four closed-track Arabic sentence-segmentation subtasks of AraSeg 2026. Heterogeneous ensembles combining LoRA-adapted bidirectional language models, XLM-R variants, a character-level SaT model, and punctuation-aware models outperform their development-selected single-model baselines. Large weights assigned to weaker but architecturally distinct members are consistent with complementary errors, although they do not establish causality. A training-only logistic MEMM improves F1 by +0.9 and +0.6 points on the punctuation-free subtasks but degrades both punctuated ones; the same directional pattern appears on the blind split. Aligning punctuated and punctuation-free inputs reveals F1 points of oracle headroom against the contemporaneous NoPnx locks, while only 52.5% of removed tokens are covered by the restoration label inventory. Genre-proxy analysis localizes the largest degradation to scriptural text. On the blind split, in the closed track, our systems achieved F1 scores of 94.4/91.3/89.9/87.0 on PA, NP, NoPnx-PA, and NoPnx-NP, respectively, ranking 6th/3rd/4th/3rd. The same systems, entered unchanged in the open track, rank 4th/2nd/3rd/3rd. Implementation and experimental resources are publicly available.[<https://github.com/NAMAA-ORG/NAMAA-Community-AraSeg-2026>]
Anthology ID:
2026.arabicnlp-sharedtasks.112
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:
912–921
Language:
URL:
https://aclanthology.org/2026.arabicnlp-sharedtasks.112/
DOI:
Bibkey:
Cite (ACL):
Muhammed Ragab, Khloud Al Jallad, Karim Elsayed, and Omer Nacar. 2026. NAMAA Community at AraSeg Shared Task 2026: Model Diversity, Conditional Decoding, and Missing Punctuation in Arabic Sentence Segmentation. In Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks, pages 912–921, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
NAMAA Community at AraSeg Shared Task 2026: Model Diversity, Conditional Decoding, and Missing Punctuation in Arabic Sentence Segmentation (Ragab et al., ArabicNLP 2026)
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PDF:
https://aclanthology.org/2026.arabicnlp-sharedtasks.112.pdf