Binary success metrics hide whether manipulation failures come from poor strategy or from commanding movements the object's physics don't allow—CRS separates these by measuring constraint-aligned vs. wasted motion, enabling better policy diagnosis without needing demonstrations or learned judges.
This paper introduces Constraint-Referenced Strategy (CRS), a new way to evaluate robot manipulation policies that goes beyond simple success/failure. Instead of just checking if a task succeeded, CRS measures how well a robot's commanded movements align with an object's physical constraints—like how a door hinge only allows rotation around one axis.