You're right, probably not from a blank canvass, no. But consider....say Warren trained you early on, and continued to do so throughout the years. You improved both through your experience and Warren's experience. Now you've been at it a decade and you're becoming really good.
Then, years later, he sends you a DVD he thinks you should enjoy and study. I betcha' you could learn from it. I betcha'.
As with most discussions, we probably need to clarify premises and meanings, particularly the word
learn, yes?
I don't believe that one could learn trumpet or martial arts from DVDs, if DVDs were the only source. To me, the statement "learn martial arts from DVDs" means that the DVDs are the only source and in this instance, to learn something means to have
internalized it so that one can
perform at an intermediate-to-high level.
However, as you have suggested, I do agree that one can sense, attend to, retain and be able to recall
information from a DVD, and this aligns with the idea of learning circuit theory. In Warren's case, the information might be "compress your chops from the sides instead of the top and bottom." That would be good information. But after watching the DVD, did I learn to
do that, or did I just sense, attend to, retain and be able to recall the
information that I
should compress my chops like that, and did I just
attempt to compress my chops like that? Only
Warren would be able to tell if I actually learned to
do that to a level where I can achieve the goal: to produce a good, strong tone over the range of my instrument. To do that, Warren would have to be present to evaluate my progress.
However (2), I am willing to concede that if I had
Warren's skill at judging tone, I might be able to evaluate
myself and determine if I am actually achieving the goal. Now that would be the moderator of the effect of the DVD: the ability to self-evaluate.
Yes?