Tathabbut at at IslamicEval 2026: Canonical-Provenance Evidence Fusion for Fine-Grained Citation Hallucination Verification

Salma Khaled Hegazy


Abstract
Islamic question-answering systems can produce fluent Arabic while altering Qur’anic wording, Hadith text, narrator chains, or source attribution. We present Tathabbut for two IslamicEval 2026 settings: fine-grained verification and canonical correction. For verification, Canonical-Provenance Evidence Fusion (CPEF) classifies Ayah, matn, isnad, and claimed-source segments by combining canonical retrieval with collection, narrator, response-level, contradiction, and exact-matn provenance evidence. CPEF achieves 0.9452 macro accuracy on the official Test set. For correction, Type-Aware Selective Canonical Retrieval (TASCR) reranks authoritative Qur’anic and Hadith candidates using lexical, memory-based, contextual, and source evidence, and abstains when confidence is insufficient. TASCR achieves 86.29% Test accuracy. A post-hoc Development diagnostic finds the gold correction for 319/327 (97.55%) recoverable cases in an expanded candidate pool, indicating that candidate discrimination and abstention are larger bottlenecks than retrieval recall. Neither submitted component invokes a generative LLM at inference time.
Anthology ID:
2026.arabicnlp-sharedtasks.132
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:
1075–1080
Language:
URL:
https://aclanthology.org/2026.arabicnlp-sharedtasks.132/
DOI:
Bibkey:
Cite (ACL):
Salma Khaled Hegazy. 2026. Tathabbut at at IslamicEval 2026: Canonical-Provenance Evidence Fusion for Fine-Grained Citation Hallucination Verification. In Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks, pages 1075–1080, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Tathabbut at at IslamicEval 2026: Canonical-Provenance Evidence Fusion for Fine-Grained Citation Hallucination Verification (Hegazy, ArabicNLP 2026)
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PDF:
https://aclanthology.org/2026.arabicnlp-sharedtasks.132.pdf