HP at BAREC Shared Task 2026: Parameter-Efficient Ordinal Regression and Threshold Optimization for Arabic Readability.

Hoàng Phong Đinh, Thìn Đặng Văn


Abstract
This paper describes the system submitted by team HP for the BAREC Shared Task 2026 on Arabic readability assessment. Driven by the Quadratic Weighted Kappa (QWK) eval- uation metric, which heavily penalizes dis- tant misclassifications, we reframe the 19- level task as an ordinal regression problem rather than standard multi-class classification. Our approach leverages pre-trained language models (AraBERTv02, ARBERT) optimized via Parameter-Efficient Fine-Tuning (LoRA) and trained with a COnsistent RAnk Log- its (CORAL) loss framework incorporating sample-level class weights. To ensure robust generalization, we consolidate the available datasets and implement a 5-fold stratified cross- validation pipeline. Finally, to optimize the QWK metric on the official blind test, we apply an 18-threshold Nelder-Mead optimizer cali- brated exclusively on blended Out-Of-Fold log- its, yielding a blind test QWK of 0.837. Our solution is released in the Github.
Anthology ID:
2026.arabicnlp-sharedtasks.17
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:
160–164
Language:
URL:
https://aclanthology.org/2026.arabicnlp-sharedtasks.17/
DOI:
Bibkey:
Cite (ACL):
Hoàng Phong Đinh and Thìn Đặng Văn. 2026. HP at BAREC Shared Task 2026: Parameter-Efficient Ordinal Regression and Threshold Optimization for Arabic Readability.. In Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks, pages 160–164, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
HP at BAREC Shared Task 2026: Parameter-Efficient Ordinal Regression and Threshold Optimization for Arabic Readability. (Đinh & Văn, ArabicNLP 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.arabicnlp-sharedtasks.17.pdf