Richard Feynman Didn't Want His Best Students Scoring 10/10 !
During his PhD at Caltech, Prof. Deepak Dhar worked as a teaching assistant under legendary physicist Richard Feynman.
He initially graded answers as 0, 0.5 or 1. But Feynman encouraged him to use a continuous scale out of 10, with nobody receiving a perfect score.
His believed that grades should distinguish different levels of understanding, while reminding even the brightest students that there is always room to improve.