in doing research for my thesis, i was looking at web psychology and how using this medium requires fundamentally different mental processes. consequently, people read material online differently than they would if it were in a book. they scan, generally. it's about breadth, more than depth. i was not able to use this material in my thesis work, but i thought it was interesting. here's the link.
the website's summary is itself very demonstrative of the principles it advocates, kind of like scott mccloud, with his don't-just-say-it-show-it kind of mentality.