Experiments on the Web: How to

This is a great 2007 guide by Ron Kohavi et al. on how to perform controlled experiments on the Web and trust the data instead of the wise man: "Practical Guide to Controlled Experiments on the Web: Listen to Your Customers not to the HiPPO". Protocol, statistics, measures, pitfalls, anecdotes. It has it all.

Incremental Collaborative Filtering

New paper "Item-based and user-based incremental collaborative filtering for Web recommendations" to be published in EPIA 09 (Springer). This is an extension of another paper at Web Intelligence 08 in Sydney (very nice place). The idea is to employ an item-based approach and update the relevant entries of the similarity matrix as new sessions pop-up. Clearly better than he user based approach.