ALEXIS at DialectSentEval Subtask 1 Adversarial Training and Iterative Self-Training for Zero-Shot Dialect Sentiment Analysis

Momen Ibrahim, Mariam E. Hassib, Ahmed Mahmoud Salem, Marwan Torki


Abstract
Dialect sentiment analysis asks for the polarity of a sentence written in a regional Arabic variety rather than Modern Standard Arabic. We present a system for Subtask 1 of DialectSentEval built on two observations about the data. First, the task is one of zero-shot transfer rather than classification: the test set introduces Lebanese, a dialect with no labeled training data and the highest out-of-vocabulary rate in the task (52.0% of word types, against 19.5–41.0% for the seen dialects). Second, k-fold cross-validation cannot see this, since it measures generalization to unseen sentences and never to an unseen dialect. We therefore validate with a leave-one-dialect-out diagnostic and score every component on the official leaderboard. Three dialectally diverse encoders (MARBERTv2, CAMeLBERT-DA, AraBERTv2) are trained with Fast Gradient Method adversarial training, then refined by confidence-filtered self-training on the unlabeled test set and character-level noise augmentation. Adversarial training contributes +0.040 Macro F1 over a gold-only ensemble, self-training a further +0.027, and per-class pseudo-label filtering +0.018. The final system reaches 0.8667 Macro F1, ranking 1st of 12 submissions, 4.6 points above the runner-up.
Anthology ID:
2026.arabicnlp-sharedtasks.187
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:
1462–1466
Language:
URL:
https://aclanthology.org/2026.arabicnlp-sharedtasks.187/
DOI:
Bibkey:
Cite (ACL):
Momen Ibrahim, Mariam E. Hassib, Ahmed Mahmoud Salem, and Marwan Torki. 2026. ALEXIS at DialectSentEval Subtask 1 Adversarial Training and Iterative Self-Training for Zero-Shot Dialect Sentiment Analysis. In Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks, pages 1462–1466, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
ALEXIS at DialectSentEval Subtask 1 Adversarial Training and Iterative Self-Training for Zero-Shot Dialect Sentiment Analysis (Ibrahim et al., ArabicNLP 2026)
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PDF:
https://aclanthology.org/2026.arabicnlp-sharedtasks.187.pdf