I previously wrote (and here) and spoke about the importance to learning of taking handwritten notes, and of summarizing concepts with drawings and schematics.
A recent article in Psychological Science provides further support for this notion. Researchers at Princeton report that students who took notes on laptops performed worse on conceptual questions than students who took notes longhand. The researchers conclude that “whereas taking more notes can be beneficial, laptop note takers’ tendency to transcribe lectures verbatim rather than processing information and reframing it in their own words is detrimental to learning”. This, and other relevant studies, are described in a recent New York Times article.