What and where to read about the algorithms for determining interest(s) of users?

Good day to all.


Maybe someone faced with the materials (books / articles / reviews) that describes the algorithms and/or approaches to the characterization of user's interests on the basis of fuzzy data (e-mails / phone calls (voice) / may, for example, on the basis of log any / lap contacts / etc)?

A lot of marketing information on this topic from the "Big Data is urgent", it helped someone to increase sales / to catch employees stealing / improving logistics, etc.

But here's information on the used algorithms, methods, and so on — as it is very little. Mostly mention of end use technologies (such as MapReduce, BigTable implementations, etc.). Regarding the algorithms, I like that not found. Can you tell me where to look?