This post is also crossposted on Medium.
Several years ago, I encountered the work of Dylan Wiliam, who researched the effect of teacher feedback on student improvement. In particular, he examined three types of feedback teachers give:
- Grades alone
- Both grades and comments
- Comments alone
The results of Wiliam’s research might seem counterintuitive: the students who showed the most growth were those who received comments alone. Even grades paired with comments — which at face value would seem to be the richest form of feedback — was just as ineffective as giving grades alone.
Wiliam concludes: “That most students virtually ignore…painstaking correction, advice, and praise is one of public education’s best-kept secrets.”
Not only do grades not encourage growth, they inhibit it. Grades take the focus off feedback. As a teacher of English language arts who prides himself on providing quality feedback, this finding is particularly disturbing.
Feedback is the breakfast of champions. — Ken Blanchard
But it doesn’t surprise me: frequently a student who receives an assignment back glances at the letter grade and then stows it away without ever reading the comments. This remains true even though, for most of my career, I have allowed students to revise and improve their scores on assessments.
Something about the letter grade causes learning to stop.