Are Grades Necessary for Learning?

Visitors can see the related video here:  Dan Pink Video

I really like this question, because it gets right at the nature of what learning exactly is and how it can be cultivated and is often  misunderstood.  When I think back on some of the most important learning I did as a young person, I certainly don't recall getting a grade related to it.  Reading, basic math, riding a bicycle, these are all things that I learned mostly at home, away from the school environment.  And yet they were very significant and affected the rest of my learning and quality of life tremendously.  On the flip side, like Pink's argument here, many things I spent hours trying to get A's for (I wont say that I got that many of them :) I cannot say were quality learning experience because I passed the test and moved on.  We lose whatever we dont use.  I dont think that necessarily means that we didnt learn those things we studied for, but that we dont always retain learning might be an explanation. 

Would more learning be possible if we took grades out of the picture?  That is a tough one.  I think in some cases that certainly would be true.  Here is my compromise, and I want to hear anyone else who claims to not compromise their answer:  I think that learning is often quite separate from grades, but grades usually represent the very specific type of learning that the instructor is looking for.  I have often felt that I learned a great deal, but to my surprise bombed an exam!  To me that demonstrates that teachers should focus more on encouraging student thought and directing their interpretations in the right direction versus teacher-centered assessment and instruction that doesnt account for all that students are walking away with in their process of engagement. We really cant teach them too much, but we can make them think, so I believe alot more learning could be possible if we focus on the process rather than having them end up at too narrow of a destination.