Email from John Worsley.
I teach a class on Data Mining <http://www.stanford.edu/class/cs345a> at Stanford. Students in my class are expected to do a project that does some non-trivial data mining. Many students opted to try their hand at theNetflix Challenge <http://www.netflixprize.com/> : to design a movie recommendations algorithm that does better than the one developed by Netflix.
Here’s how the competition works. Netflix has provided a large data set that tells you how nearly half a million people have rated about 18,000 movies.
Based on these ratings, you are asked to predict the ratings of these users for movies in the set that they have not rated. The first team to beat the accuracy of Netflix’s proprietary algorithm by a certain margin wins a prize of $1 million!