Hindsight relabeling for failed VLA rollouts
VLA teams with low early success rates should add a relabeling stage to RL post-training. A VLM reviews a failed rollout, writes an instruction for the behavior the robot completed, and scores the rollout against that instruction; the policy then trains on both the original task signal and the relabeled example. Learning from Hindsight kept 70%–80% of rollout groups usable, reached standard GRPO’s final LIBERO-PRO performance in about five training steps versus nearly 30, and achieved 56% success with 160 physical-robot rollouts compared with 22% for GRPO.
A low-cost check can run on stored failures before collecting more robot data. Relabel a few hundred trajectories, manually inspect a stratified sample for instruction and reward accuracy, then compare usable-group rate and held-out task success with the current reward pipeline. Deployment should keep relabeling focused on coherent completed behavior and reject ambiguous clips, since incorrect hindsight instructions would train the policy on mislabeled actions.