I'm surprised there's any doubt about this. If I want to learn something in earnest I always write it out. Whilst typing gives me neat notes I forget what I've typed much more quickly.<p>It's especially so with math equations etc. Typing math with say MathML or AsciiMath is easy but I've found that it's no match when compared to handwritten workings out.<p>Same goes for tech drawings and circuit diagrams. I work stuff out on paper first and then tidy up with CAD.<p>It seems to me the mechanism—typewriter, computer, screen, etc.—gets in the way of one's cognitive processes and requires additional mental resources.