Abstract
Sentiment swap is the task of rewriting a sentence so that it carries the opposite polarity while its topic stays the same. We present a system for Arabic sentiment swap built on two observations about the data. First, the swap is a local edit rather than a paraphrase: 91% of reference rewrites stay within two words of their source. Second, the polarity to swap away from has to be predicted, because the test data does not provide it. We therefore fine-tune mT5 and refine it with Direct Preference Optimization under a reward that balances target-polarity probability against content preservation. At inference we pool candidates from four generators, one of them a minimal-edit tagger, together with a retrieval index, rerank them with the same balance, and repair them with polarity-flip lexicons mined from the training set. Source polarity is supplied by a dedicated classifier that reaches 97.3% accuracy, against 74.3% for the off-the-shelf sentiment model that the evaluation itself uses. Every component was scored on the official leaderboard: generation-side work contributes +0.044 Sentiment Style Accuracy, and the dedicated polarity classifier a further +0.155. The final system reaches 0.9581 Sentiment Style Accuracy, 56.91 BLEU and 72.18 chrF, ranking 1st of 15 submissions.
- Anthology ID:
- 2026.arabicnlp-sharedtasks.188
- Volume:
- [Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks](https://aclanthology.org/volumes/2026.arabicnlp-sharedtasks/)
- 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](https://aclanthology.org/venues/arabicnlp/)
- SIG:
- [SIGARAB](https://aclanthology.org/sigs/sigarab/)
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 1467–1472
- Language:
- URL:
- [https://aclanthology.org/2026.arabicnlp-sharedtasks.188/](https://aclanthology.org/2026.arabicnlp-sharedtasks.188/)
- DOI:
- Cite (ACL):
- Momen Ibrahim, Mariam E. Hassib, Ahmed Mahmoud Salem, and Marwan Torki. 2026. ALEXIS at DialectSentEval Subtask 2 Retrieval-Augmented, Preference-Tuned Generation for Arabic Sentiment Swap . InProceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks , pages 1467–1472, Budapest, Hungary. Association for Computational Linguistics.
- Cite (Informal):
- ALEXIS at DialectSentEval Subtask 2 Retrieval-Augmented, Preference-Tuned Generation for Arabic Sentiment Swap (Ibrahim et al., ArabicNLP 2026)
- PDF:
- [https://aclanthology.org/2026.arabicnlp-sharedtasks.188.pdf](https://aclanthology.org/2026.arabicnlp-sharedtasks.188.pdf)