Information problem and movement problem

The piano teacher in the post below, Dr. John Mortensen, distinguishes between information problems and movement problems.

The information problem is when you can't read the music. You don't know, in a literal sense, what those notes are, or how to count that particular rhythm.  He says that practicing is problem solving, so you solve that problem by figuring it out.

A movement problem is when you can't physically play something on the piano.  You can't make your fingers do that easily. So you solve that problem by fingering, grouping, etc... getting to the point where you fingers will play it correctly at a slowed down tempo.

The main take-away is that practice is problem solving.  I had not thought about this before, though I had distinguished in my mind between things I couldn't play because I couldn't read them, and things that I couldn't play because I couldn't play them physically.  It is helpful to know what kind of problem you have.

I play through the easy lines over and over, and then work for a bit on the hard parts. Obviously this is backwards. As he explains in another video, you have to divide the piece into playable parts and non-playable parts, and only work on the non-playable parts until they become playable.

There's another kind of practice where, once I know a piece well and have memorized it, I play it in order to rehearse it for recording or performance, even if the performance is only for my teacher in my lesson.  This guy says that your performances will reflect how you have practiced. So he can hear a student play and immediately know how the student practiced, what sh/e did or did not do.