cs.CVOct 27, 2026

Evaluation-Guided Demonstration Refinement for Vision-Language-Action Policies: The Winning Entry in the MetaFine Open Competition

Authors: Lifan Zheng, Guotao Chen, Zhenyang Li, Shujie Cui, Qiang Huang, Fan Liu

Organizations: Southeast University · The Hong Kong Polytechnic University · Monash University · Harbin Institute of Technology (Shenzhen)

Abstract

We fine-tuned a separate π0.5π_{0.5} policy for each of the five tasks in the MetaFine Open Competition, with a task-specific training mixture and number of actions executed per prediction. Training started from the official demonstrations and expert procedures. Local evaluation exposed recurring grasping, pushing, and insertion failures. We addressed them by revising the demonstrated motions and by adding expert continuations from states the policy reached, while keeping nominal demonstrations in training. Checkpoints were compared on every instruction, so that a gain on one instruction could not hide a loss on another. Our submission, MAI, ranked first overall with a score of 96.66.

Figures & tables

Explore similar work

CardsList
  1. FailPatch: Failure Residual Patching for Vision-Language-Action Models

    Sep 28, 2026Peng Yu, Jiacheng Wang, Ziheng Zhang +6Robot Policy LearningRobot Policy Adaptation