This is a segment from NPR's HIdden Brain about Dr. Martin Levy's use of a clicker, usually used to train dogs, to train surgical students. It's fascinating. Essentially, the argument is made that clickers work so well because it is a form of feedback that does not use any verbal signals - no praise, no reprimand, no "good job," no "not like that." Praise and criticism distract a learner from mastering the skill being taught, making a learner focus instead on pleasing the teacher. With nonverbal feedback, the learner doesn't focus on the teacher but on the skill being taught