Walking robots can easily move around on a flat surface, but in the field there are countless obstacles and uneven ground. In a new paper, a control system is created that lets the robot use sensory information to determine not just the ground itself but the accuracy of that sensory data. If it becomes too inaccurate or misleading, it can slow down and move more carefully until its perception improves. This is just one way to help robots move in unfamiliar terrain, making slow but robust progress.