Collaborative Filtering and rise of Ensembles

igrigorik writes: "First the Netflix challenge was won with the help of ensemble techniques, and now the GitHub challenge is over and over half of the top entries are also all based on ensembles. Good knowledge of statistics, psychology and algorithms is still crucial, but the ensemble technique alone has the potential to make the collaborative filtering space, a lot more, well, collaborative! A look at the basic theory behind ensembles, how they shaped the results of the GitHub challenge, and how this pattern can be used in the future."