Aijia Wang

Author directory

2026

Reward modeling is essential for multimodal alignment, yet most existing reward models only provide outcome reward, which is sparse and fails to capture human preferences. Rubrics can provide structured and fine grained evaluation signals, but building effective rubrics for multimodal tasks is challenging. In this work, we propose **MM-VeriRubric**, a framework for scalable construction of training data for multimodal rubric generation and rubric-based reward models. To better use visual evidence in images, we introduce task-aware visual clue extraction, which makes rubric generation more grounded in task-relevant visual information. MM-VeriRubric then generates evidence-grounded rubrics and constructs rubric-aligned rejected responses with controlled error dimensions, enabling the quality of each rubric to be verified through consistency checking. The verified data are used to train both a rubric generator and a rubric-based reward model. Experiments on multimodal reward model benchmarks and downstream Best of N tasks show that MM-VeriRubric improves preference judgment (+16.4% on VL-RewardBench) and provides more interpretable and diagnostic reward signals for multimodal alignment (+13.1% on MMMU-Pro using Best of 5 selection). Code is available at: https://github.com/TraceLite-AI/MM-VeriRubric.