: My approach was something like: : 1) Look at the categories that the user has preferred and compute the : z-score : 2) Pick the top 3 among those : 3) Use those to boost search results.
I think that totaly makes sense ... the additional bit i was suggesting that you consider is that instead of picking the "highest" 3 z-scores, pick the z-scores with the greatest absolute value ... that way if someone is a very booring person and their "positive interests" are all basically exactly the same as the mean for everyone else, but they have some very strong "dis-interests" you don't bother boosting on those miniscule interests and instead you negatively boost on the things they are antogonistic against. -Hoss
