I discussed the process of learning with my brother recently. He is a professor of physics, who focuses his research on the human voice. He is currently writing a book for voice practitioners and he shared a chapter with me on motor-learning which I felt helped me in my piano teaching.
"Motor learning is a process, inferred rather than directly observed, which leads to relatively permanent changes in the general capacity for motor performance, as a result of practice or exposure."
New action patterns are not incremental and they do not accumulate some place in the head in an ordered way. They are dynamic, they fluctuate, but real, permanent learning means that various mental processes will occur consistently as a result of practice. Temporary performance shifts that may occur during lessons do not imply learning. Learning involves relatively stable changes and improvements in average performance over time. I had a student who has since moved away who would try to wing it at his lesson. As he played his piece for me I knew, and he knew I knew, that he had not practiced enough. "Wait," he would say, "Let me do that again and maybe this time I will be lucky."
Improvement over a short period of time, such as during a lesson or a week long practice session, does not mean real motor learning is permanent. Distractions can impact learning. The best measure of how well something is learned is demonstrated by the first try with multiple distractions.
Most studies hold to the principle that spaced practice tends to produce greater learning than massed practice. If a student is attentive and working on a problem he will be more productive if he works on it 10 minutes and then rests and comes back later in the day, than if he practices 60 minutes and does not go back for several days. The brain will work on the problem when the student is away from the piano. I felt a little discouraged when I read that because my student's lives are so full. Would they ever go back to practice on the same day?
Verbal instructions from a teacher are not as effective as curiosity, from the student, to try different approaches and find the answer themselves. Attention to the experience the student is having is more effective than telling the student what to pay attention to. Asking questions such as "did that feel better" "was that easier", or "did it sound better" are more effective than "was your hand curved". Paying attention to the experience is better for processing than paying attention to the physical action.
Watching others has been shown to be very motivational. Self goal-setting works better than having a goal assigned. Giving feedback while the student is playing interferes with his own processing of information. Waiting until after they are done, works better and asking them to evaluate their own playing first, helps them even more.
Provide some variability in the lesson setting. Playing with different conditions enhances learning. I think we all know that when a student is practicing for a recital it is wise to practice in different situations; in front of family, on a different piano, or while someone is speaking.
Random practice, or playing pieces and exercises in a different order, is effective because it forces the learner to "reboot" and reconstruct his learning which he may not have to do if he has a rote practice agenda.
Part-whole practice is effective for learning. Dividing a piece into sections and starting on a different section helps long term learning.
These are just ideas researchers are working on. My brother is summarizing those that have had the most consistent results. He is hoping to help vocal coaches and vocologists who have students and clients who need to learn new motor skills having to do with their vocal mechanisms.
I find these ideas most interesting and it explains many occurrences in my experience. One, for example, is the way note-reading seems to come and go, in a beginning student. They seem to be able to do it at our lesson, but then it falls apart at home. So, real learning did not take place at the lesson. The test of stability, getting it right on the first try, even with distractions, is the ultimate measuring tool.