Duncan Green on positive deviance

"The model was taken on and applied by the Vietnamese National Institute of Nutrition, and after this by the government, which scaled it nationally. Over time, the positive deviance approach saw a sustained reduction in malnutrition rates of 65–80 per cent, and reached a population of 2.2 million." from http://www.oxfamblogs.org/fp2p/?p=16533 Wikipedia article on positive deviance.