NAMAA Community at DialectSentEval 2026 Subtask 1: Dialect-Aware Arabic Sentiment Classification with Pretrained Transformer Models

Mona A.Azim, Hassan Barmandah, Yousra Alaa El-Ghawi, Omer Nacar


Abstract
Arabic dialect sentiment analysis is challenging because regional varieties show considerable lexical, morphological, syntactical, and orthographic variation. This paper presents a transformer-based system developed for DialectSentEval 2026 Subtask 1, a three-class sentiment classification task covering Moroccan, Egyptian, Jordanian, and Saudi Arabic. The system independently fine-tunes three pretrained Arabic language models: AraBERTv2, MARBERTv2, and CAMeLBERT, using a common training protocol. The implementation uses an 80/20 stratified train-validation split, a maximum sequence length of 128, a batch size of 16, a learning rate of 2 × 10-5, and focal loss with 𝛾=2=2. Model selection was conducted based on validation macro F1. Using the published labeled test set, MARBERTv2 achieves the strongest independent result with 94.07% macro F1, followed by CAMeLBERT at 81.96% and AraBERTv2 at 79.77%. The results demonstrate the importance of Arabic pretraining and dialect-oriented representations and establish MARBERTv2 as the strongest standalone backbone in the current system.
Anthology ID:
2026.arabicnlp-sharedtasks.181
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:
1431–1435
Language:
URL:
https://aclanthology.org/2026.arabicnlp-sharedtasks.181/
DOI:
Bibkey:
Cite (ACL):
Mona A.Azim, Hassan Barmandah, Yousra Alaa El-Ghawi, and Omer Nacar. 2026. NAMAA Community at DialectSentEval 2026 Subtask 1: Dialect-Aware Arabic Sentiment Classification with Pretrained Transformer Models. In Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks, pages 1431–1435, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
NAMAA Community at DialectSentEval 2026 Subtask 1: Dialect-Aware Arabic Sentiment Classification with Pretrained Transformer Models (A.Azim et al., ArabicNLP 2026)
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PDF:
https://aclanthology.org/2026.arabicnlp-sharedtasks.181.pdf