Have you ever asked your students to answer this question? You might want to give it a try, I think you would be pleasantly surprised by the answer. I know I sure was. A couple of weeks ago, I asked my grade twos this question (It comes from the Inspiring Education document from the Alberta Government) and I wanted them to video tape each other and post it to their blogs (Yes.. you read that correctly, I have my students video tape themselves all the time). If you are interested in going to take a look here are the videos on How Do I Learn.
After reviewing the video, I picked those I felt the students needed to hear because of what was said. Here is what the students said:
We then talked about, what evidence shows your learning? I was blown out of the water by what these little people came up with. Yes... all my reinforcing of vocabulary has paid off.
You might want to try asking your students, how they learn and have a conversation about it one class. It think it would make for an interesting discussion.