a nonparametric hierarchical bayesian framework for information filtering
Information filtering has made considerable progress in recent years. The predominant approaches are content-based methods and collaborative methods. Researchers have largely concentrated on either of the two approaches since a principled unifying framework is still lacking. This paper suggests that both approaches can be combined under a hierarchical Bayesian framework . Individual content-based user profiles are generated and collaboration between various user models is achieved via a common learned prior distribution. However, it turns out that a parametric distribution (e.g. Gaussian) is too restrictive to describe such a common learned prior distribution. We thus introduce a nonparametric common prior , which is a sample generated from a Dirichlet process which assumes the role of a hyper prior . We describe effective means to learn this nonparametric distribution, and apply it to learn users' information needs. The resultant algorithm is simple and understandable, and offers a principled solution to combine content-based filtering and collaborative filtering. Within our framework, we are now able to interpret various existing techniques from a unifying point of view. Finally we demonstrate the empirical success of the proposed information filtering methods.
parametric hierarchic information filter filtering method collaboration research paper users user model learning distributed sampling dirichlet process role effect information need algorithm content-based filtering collaborative filtering point demonstrate  framework  nonparametric bayesian modelling contention user-profile