VMMU: A Vietnamese Multitask Multimodal Understanding and Reasoning Benchmark

Vy Tuong Dang, An Vo, Emilio Villa-Cueva, Quang Tau, Duc Dm, Thamar Solorio, Daeyoung Kim


Abstract
Vision language models are predominantly evaluated on English-centric multimodal benchmarks, leaving their behavior in other languages and cultures insufficiently understood. We introduce VMMU, a Vietnamese Multitask Multimodal Understanding and Reasoning benchmark of 2,548 multiple-choice questions across seven domains: Mathematics, Physics, Chemistry, Biology, Geography, Driving Test, and IQ Test. Every question requires jointly reasoning over Vietnamese text and non-text visual evidence (charts, diagrams, tables, traffic scenes), and is distributed as a single rendered page image. We evaluate 10 open-source and 5 closed-source VLMs on VMMU. Test-time compute improves performance from 57% to 78% accuracy, but it remains inferior to an expert baseline (99% accuracy). Extensive error analyses show that closed-source VLMs already achieve strong Vietnamese OCR performance, yet still struggle on VMMU. This suggests that the primary bottleneck is multimodal grounding and reasoning rather than text recognition or Vietnamese language understanding. Code and data are available at: https://vmmu-bench.github.io.
Anthology ID:
2026.findings-aacl.44
Volume:
Findings of the Association for Computational Linguistics: IJCNLP-AACL 2026
Month:
November
Year:
2026
Address:
Hengqin, China
Editors:
Yue Zhang, Ruifeng Xu, Ayu Purwarianti, Tong Rong, Jun Suzuki
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
825–870
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URL:
https://aclanthology.org/2026.findings-aacl.44/
DOI:
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Cite (ACL):
Vy Tuong Dang, An Vo, Emilio Villa-Cueva, Quang Tau, Duc Dm, Thamar Solorio, and Daeyoung Kim. 2026. VMMU: A Vietnamese Multitask Multimodal Understanding and Reasoning Benchmark. In Findings of the Association for Computational Linguistics: IJCNLP-AACL 2026, pages 825–870, Hengqin, China. Association for Computational Linguistics.
Cite (Informal):
VMMU: A Vietnamese Multitask Multimodal Understanding and Reasoning Benchmark (Dang et al., Findings 2026)
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https://aclanthology.org/2026.findings-aacl.44.pdf