Quantify the dependence of visual OPE accuracy on dataset coverage

Quantify how RoboFQE’s value-estimation accuracy depends on the offline dataset’s coverage of state-action regions visited by the target policy under visual observations.

Background

RoboFQE estimates policy returns from a fixed offline dataset, so its accuracy depends on whether that dataset contains sufficient coverage of the state-action regions encountered by the evaluated policy. The paper’s experiments demonstrate that limited coverage and out-of-support actions can produce extrapolation errors, but they do not provide a systematic characterization of this dependence for visual robot manipulation.

The unresolved problem is therefore to quantify the relationship between offline state-action coverage and value-estimation accuracy in visual observations, which would help establish reliability criteria for rollout-free evaluation and clarify when RoboFQE can be trusted.

References

We note three limitations of our study. First, value-based OPE accuracy depends on the offline dataset's coverage of state-action regions visited by the target policy; quantifying this dependence under visual observations remains an open question.

— RoboFQE: Rollout-Free Evaluation of Visual Robot Policies from Offline Trajectories  (2610.18699 - Deng et al., 13 Oct 2026) in Conclusion and Limitations, first limitation

Our study does not establish whether RoboFQE can reliably rank policies on tasks absent from the offline dataset, or how its generalization compares with that of large-scale pretrained world-model evaluators.

— RoboFQE: Rollout-Free Evaluation of Visual Robot Policies from Offline Trajectories  (2610.18699 - Deng et al., 13 Oct 2026) in Conclusion and Limitations, first limitation