NU-SentEval at DialectSentEval Shared Task Subtask-2: Fine-Tuning AraT5 for Arabic Dialect Sentiment Swap

Areej Khaled, Maraim Mazen, Alaa Tamer, Ensaf H. Mohamed


Abstract
We present NU-SentEval’s system for DialectSentEval 2026 Subtask 2 (Arabic Dialect Sentiment Swap), which rewrites Arabic dialectal sentences into the opposite sentiment polarity while preserving their core content. Our approach fine-tunes AraT5v2-base-1024, a pretrained Arabic sequence-to-sequence model, directly on the shared task’s source-target sentence pairs, and generates outputs using standard beam search decoding. On the official Final Evaluation test leaderboard, our system achieves 54.63 BLEU, 72.61 chrF, and 68.98% sentiment preservation. Our manual error analysis shows the model reliably inverts sentiment for short, single-clause inputs, often matching the human reference exactly, though it occasionally fails to propagate the sentiment flip to secondary cues such as emojis, resulting in mixed-signal outputs.
Anthology ID:
2026.arabicnlp-sharedtasks.185
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:
1452–1456
Language:
URL:
https://aclanthology.org/2026.arabicnlp-sharedtasks.185/
DOI:
Bibkey:
Cite (ACL):
Areej Khaled, Maraim Mazen, Alaa Tamer, and Ensaf H. Mohamed. 2026. NU-SentEval at DialectSentEval Shared Task Subtask-2: Fine-Tuning AraT5 for Arabic Dialect Sentiment Swap. In Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks, pages 1452–1456, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
NU-SentEval at DialectSentEval Shared Task Subtask-2: Fine-Tuning AraT5 for Arabic Dialect Sentiment Swap (Khaled et al., ArabicNLP 2026)
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PDF:
https://aclanthology.org/2026.arabicnlp-sharedtasks.185.pdf