Ahmed Younis at ImageEval 2026 Shared Tasks: The Judge Needs a Prior and the Task Needs a Constraint

Ahmed Younis


Abstract
Across two ImageEval 2026 tracks, our best results came from analyzing the evaluation machinery rather than from a stronger model, yielding 1st place on hallucination detection (Task 1b, Modern Standard Arabic) and 4th on CRAI-Bench (Task 2). On CRAI-Bench, which asks systems to predict human cultural-accuracy scores for AI-generated images of Qatari scenes, a blind frequency prior that never looks at an image reaches dev Spearman 0.6878, above the organizers’ GPT-4-as-judge baseline of 0.625; adding two vision judges, with blend weights tuned against the global ranking metric rather than by scene-level cross-validation, reaches 0.7806 on the blind test. The weighting correction alone is worth +0.0296 test Spearman, because scene-level cross-validation is structurally blind to the within-cell ranking that judges contribute. On Task 1b, reframing "label three statements true/false" as "select the one grounded statement" makes invalid labelings structurally impossible and reaches 0.964 combined accuracy on the blind test, against an official baseline of 0.508. A matched-model ablation shows most of that headline gap is the underlying judge, but the constraint still adds +0.026 combined accuracy and eliminates the 4.0% of items that otherwise receive structurally invalid labelings; meanwhile upgrading to a stronger judge is worth nothing measurable and a three-model vote scored lower.
Anthology ID:
2026.arabicnlp-sharedtasks.94
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:
753–758
Language:
URL:
https://aclanthology.org/2026.arabicnlp-sharedtasks.94/
DOI:
Bibkey:
Cite (ACL):
Ahmed Younis. 2026. Ahmed Younis at ImageEval 2026 Shared Tasks: The Judge Needs a Prior and the Task Needs a Constraint. In Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks, pages 753–758, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Ahmed Younis at ImageEval 2026 Shared Tasks: The Judge Needs a Prior and the Task Needs a Constraint (Younis, ArabicNLP 2026)
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PDF:
https://aclanthology.org/2026.arabicnlp-sharedtasks.94.pdf