Overcoming the Reality Gap for Simulation-Based Policy Evaluation

Develop calibration and alignment techniques that overcome the reality gap specifically for simulation-based evaluation of robotic policies, ensuring that performance measured in simulation reliably matches performance in the real environment.

Background

Simulation is increasingly used to evaluate policies intended for real-world deployment, offering reproducibility and scale. However, without careful alignment, simulation may not be a reliable proxy for real-world performance, undermining evaluations.

The authors explicitly call out the need to bridge the reality gap for the downstream purpose of model evaluation, so that simulation-derived metrics accurately predict real-world behavior.

References

While methods to reduce this gap are very similar to the ones used for sim-to-real transfer, an open question is how to overcome the reality gap for the specific downstream purpose of model evaluations such that the performance of a policy in simulation matches the performance in the real environment.

— The Reality Gap in Robotics: Challenges, Solutions, and Best Practices  (2510.20808 - Aljalbout et al., 23 Oct 2025) in Section 7.5 (Simulation for Large Robotics Models)

Sim-to-real evaluation reads the sim-to-real gap directly, as the agreement between a ranking obtained in simulation and a ranking obtained on the robot, a metric that \citet{yang2025simtorealeval} propose but have not yet measured.

— No Free Checker: A Survey of Verifiers for Robot Policies  (2609.09250 - Wan et al., 8 Sep 2026) in Section 7.1, subsection "Agreement on a Fixed Set of Rollouts"

It also exceeds matched Domain Adaptation with Rewards from Classifiers (DARC) return in every environment, but its return differences from direct target Model-Based Policy Optimization (MBPO) remain unresolved.

— Calibration-risk routing for controlled world-model adaptation  (2610.01001 - Zhang et al., 1 Oct 2026) in Abstract; Section 5.1, “Held-Out Main Comparison”; Section 6, “Discussion”