" Researchers discovered that one particular form of feedback boosted student effort and performance so immensely that they deemed it “magical feedback.” Students who received it chose to revise their papers far more often than students who did not, and their performance improved significantly. The feedback was not complicated. In fact, it consisted of one simple phrase. I’m giving you these comments because I have very high expectations and I know that you can reach them. That’s it. Just nineteen words. "

― Daniel Coyle , The Culture Code: The Secrets of Highly Successful Groups