Hashtag AI at HalluScoring-2026: Distilling Knowledge-Graph Retrieval into Gemma 4 for Arabic Hallucination Detection

Anupam Chaudhuri, Anj Simmons, Satwik Mukherjee, Rongrong Song


Abstract
We describe our submission to HalluScoring 2026 for Arabic hallucination detection in general-culture and Islamic-knowledge question answering. Our system adapts the instruction-tuned 12B-parameter Gemma 4 model with QLoRA. Its central idea is to use the Hashtag AI knowledge-graph retrieval system only during offline data construction: we query facts related to development-set failures, create contrastive training examples, and distill them into the model parameters. The submitted model is closed-book and uses no retrieval, search, or external knowledge at evaluation time. On organizer-provided test annotations, it obtains 73.59 macro-F1 on the 400-example Islamic set and 77.56 on the 1,600-example mixed-domain set; answer-option accuracies are 75.25% and 81.13%. Analysis shows strong science performance but lower recall for subtle hallucinations in history, geography, and Islamic knowledge.
Anthology ID:
2026.arabicnlp-sharedtasks.138
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:
1120–1125
Language:
URL:
https://aclanthology.org/2026.arabicnlp-sharedtasks.138/
DOI:
Bibkey:
Cite (ACL):
Anupam Chaudhuri, Anj Simmons, Satwik Mukherjee, and Rongrong Song. 2026. Hashtag AI at HalluScoring-2026: Distilling Knowledge-Graph Retrieval into Gemma 4 for Arabic Hallucination Detection. In Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks, pages 1120–1125, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Hashtag AI at HalluScoring-2026: Distilling Knowledge-Graph Retrieval into Gemma 4 for Arabic Hallucination Detection (Chaudhuri et al., ArabicNLP 2026)
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PDF:
https://aclanthology.org/2026.arabicnlp-sharedtasks.138.pdf