From http://on.wsj.com/15ApOsp    Why Tough Teachers Get Good Results

Psychologist K. Anders Ericsson gained fame for his research showing that true expertise requires about 10,000 hours of practice, a notion popularized by Malcolm Gladwell in his book "Outliers." 

The rap on traditional education is that it kills children's' creativity. But Temple University psychology professor Robert W. Weisberg's research suggests just the opposite. Prof. Weisberg has studied creative geniuses including Thomas Edison, Frank Lloyd Wright and Picasso—and has concluded that there is no such thing as a born genius. Most creative giants work ferociously hard and, through a series of incremental steps, achieve things that appear (to the outside world) like epiphanies and breakthroughs.

Prof. Weisberg analyzed Picasso's 1937 masterpiece Guernica, for instance, which was painted after the Spanish city was bombed by the Germans. The painting is considered a fresh and original concept, but Prof. Weisberg found instead that it was closely related to several of Picasso's earlier works and drew upon his study of paintings by Goya and then-prevalent Communist Party imagery. The bottom line is that creativity goes back in many ways to the basics. "You have to immerse yourself in a discipline before you create in that discipline."