The realy work was done by Simon Papert, his essay "The Gears of My Childhood" (pdf link <a href="http://learn.media.mit.edu/lcl/resources/activity/week1/gears.pdf?pdf=gears.en" rel="nofollow">http://learn.media.mit.edu/lcl/resources/activity/week1/gear...</a>) is worth a read.<p>A quote from this essay: "The fundamental fact about learning: Anything is easy if you can assimilate it to your collection of models. If you can't, anything can be painfully difficult."