The longer I spend working with students closely the more I realize how detrimental grades really are to efficacy. Student's academic efficacy relies heavily on whether or not they "get" the right grade. The right grade is usually the one that begins the alphabet or the one right next to it. If the student doesn't earn that then their efficacy plummets.
The longer I spend working with students the more I realize how important personal feedback is to them. Just like me, they appreciate when someone tells them what they do well, what can improve, and how to improve it. They genuinely want to know how to improve their work so they can prove they are learning.
All of this stemmed from a statement I made that I never looked at my first grader's report card. I asked my students why a teacher and parent would not bother to look. After getting all kinds of answers I pointed out that my daughter can do everything on the report card because she does all of those things in front of me - I can see and hear her learning. The report card didn't squat to me because my daughter proves her learning every day.
Grades don't prove learning. Learning is proved by the evidence students present to teachers in its novice, emerging, and proficient forms. Personal interactions with students are the most powerful form of "grading" we have and every teacher should make use of this to help every student be proficient in their learning.