Optimal at AISA-ArabicFC: A Hybrid Approach to Arabic Function Calling with PEFT Large Language Models and Deterministic Post-Processing

Sarah Alowjan, Lujain Al mana, Haya Buayyan Alwizrah


Abstract
Arabic function calling requires models to identify appropriate tools and reproduce arguments in the exact representation expected by evaluators. This is challenging due to dialectal variation, lexical alternatives, and surface-form normalization. We present a hybrid system based on Qwen2.5-7B-Instruct adapted with 4-bit QLoRA, followed by conservative deterministic post-processing. The neural model generates flexible tool calls, while a lightweight deterministic layer parses, validates, and casts the output to improve compliance with the exact-match evaluation format. On the official blind evaluation, our system obtains 93.24% Function Accuracy and 58.38% Argument Exact Match (Track A: 72.32%, Track B: 71.37%). Error analysis indicates that many remaining failures arise from argument-surface mismatches rather than function-selection errors, supporting a design where generative modeling handles semantics while deterministic processing controls exact realization.
Anthology ID:
2026.arabicnlp-sharedtasks.207
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:
1603–1607
Language:
URL:
https://aclanthology.org/2026.arabicnlp-sharedtasks.207/
DOI:
Bibkey:
Cite (ACL):
Sarah Alowjan, Lujain Al mana, and Haya Buayyan Alwizrah. 2026. Optimal at AISA-ArabicFC: A Hybrid Approach to Arabic Function Calling with PEFT Large Language Models and Deterministic Post-Processing. In Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks, pages 1603–1607, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Optimal at AISA-ArabicFC: A Hybrid Approach to Arabic Function Calling with PEFT Large Language Models and Deterministic Post-Processing (Alowjan et al., ArabicNLP 2026)
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PDF:
https://aclanthology.org/2026.arabicnlp-sharedtasks.207.pdf