Soloeval at BAREC Shared Task 2026: QWK-Aligned Soft-Label Ordinal Classification with Auxiliary Surface Features for Arabic Readability Assessment

Turab Hussain Usmani


Abstract
We describe Soloeval’s submission to the Sentence-Level Open Track of the BAREC Shared Task 2026 on fine-grained Arabic readability assessment. Rather than treating the 19-level readability scale as a scalar regression target, we fine-tune pretrained Arabic BERT encoders (MARBERTv2 and CAMeLBERT-Mix) with a soft-label cross-entropy objective whose target distribution is a Gaussian centered on the gold level, chosen to more directly reflect the Quadratic Weighted Kappa (QWK) evaluation metric’s quadratic distance penalty. We combine this with lightweight auxiliary surface features (sentence length, word count, diacritic density) and K-fold cross-validation. Our best single-model configuration, CAMeLBERT-Mix trained with F=3 folds, achieves a QWK of 80.6 on the BAREC 2026 blind test leaderboard for the Open track. We report our full hyperparameter search, discuss the gap between our dev- and test-set results, and outline what we would try next.
Anthology ID:
2026.arabicnlp-sharedtasks.26
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:
225–230
Language:
URL:
https://aclanthology.org/2026.arabicnlp-sharedtasks.26/
DOI:
Bibkey:
Cite (ACL):
Turab Hussain Usmani. 2026. Soloeval at BAREC Shared Task 2026: QWK-Aligned Soft-Label Ordinal Classification with Auxiliary Surface Features for Arabic Readability Assessment. In Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks, pages 225–230, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Soloeval at BAREC Shared Task 2026: QWK-Aligned Soft-Label Ordinal Classification with Auxiliary Surface Features for Arabic Readability Assessment (Usmani, ArabicNLP 2026)
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PDF:
https://aclanthology.org/2026.arabicnlp-sharedtasks.26.pdf