If anyone is interested in what a real "machine learning" approach the problem of learning a ranking function from data looks like see this paper: Burges et. a

If anyone is interested in what a real "machine learning" approach the problem of learning a ranking function from data looks like see this paper: Burges et. al. Learning to Rank using Gradient Descent http://research.microsoft.com/apps/pubs/?id=69183 http://research.microsoft.com/apps/pubs/?id=69183 Although this is most definitely an active research area and the papers citing this one should be pretty interesting.