JAMMEval: A Refined Collection of Japanese Benchmarks for Reliable VLM Evaluation
Organizations: Kyoto University · NII LLMC · Institute of Science Tokyo · NII · Waseda University
Abstract
Reliable evaluation is essential for the development of vision-language models (VLMs). However, Japanese VQA benchmarks have undergone far less iterative refinement than their English counterparts. As a result, many existing benchmarks contain issues such as ambiguous questions, incorrect answers, and instances that can be solved without visual grounding, undermining evaluation reliability and leading to misleading conclusions in model comparisons. To address these limitations, we introduce JAMMEval, a refined collection of Japanese benchmarks for reliable VLM evaluation. It is constructed by systematically refining seven existing Japanese benchmark datasets through two rounds of human annotation, improving both data quality and evaluation reliability. In our experiments, we evaluate open-weight and proprietary VLMs on JAMMEval and analyze the capabilities of recent models on Japanese VQA. We further demonstrate the effectiveness of our refinement by showing that the resulting benchmarks yield evaluation scores that better reflect model capability, exhibit lower run-to-run variance, and improve the ability to distinguish between models of different capability levels. We release our dataset and code to advance reliable evaluation of VLMs.
Figures & tables
| Dataset | Seed Dataset | Samples | Images | Answer Format | Category |
|---|---|---|---|---|---|
| CC-OCR-JA-Refined | Yang et al. (2024) | 145 | 145 | Short answer | OCR |
| JA-VLM-Bench-Refined | Akiba et al. (2025) | 49 | 42 | Short answer | Japanese culture |
| Heron-Bench-Refined | Inoue et al. (2024) | 88 | 21 | Short answer | Japanese culture |
| CVQA-JA-Refined | Mogrovejo et al. (2024) | 200 | 94 | Multiple-choice | Japanese culture |
| JA-Multi-Image-VQA-Refined | Yuichi et al. (2024) | 53 | 39 | Short answer | Multi-image |
| JDocQA-Refined | Onami et al. (2024) | 861 | 793 | Short answer | Document |
| Accuracy (%) | Run Std | Performance Gap | Rank Corr. | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Dataset | Before | After | Before | After | Before | After | |||
| CC-OCR-Ja | 22.4 | 65.8 | +43.4 | 0.9 | 0.6 | -0.3 | 26.0 | 44.6 | 0.78 |
| JA-VLM-Bench | 64.1 | 64.9 | +0.8 | 1.6 | 0.8 | -0.9 | 28.7 | 53.1 | 0.88 |
| Heron-Bench | 46.9 | 62.2 | +15.2 | 2.0 | 0.6 | -1.4 | 43.0 | 48.9 | 0.95 |
| CVQA-JA | 62.6 | 65.3 | +2.7 | 0.9 | 0.8 | -0.1 | 58.0 | 56.7 | 0.96 |
| JA-Multi-Image-VQA | 66.5 | 71.1 | +4.6 | 1.0 | 0.5 | -0.5 | 61.2 | 52.8 | 0.99 |
Appendix figures & tables2 assets
Supplementary material from the paper’s appendix.