@techreport{shani2002an, author = {Shani, Guy and Brafman, Ronen I. and Heckerman, David}, title = {An MDP-Based Recommender System}, year = {2002}, month = {August}, abstract = {Typical recommender systems adopt a static view of the recommendation process and treat it as a prediction problem. We argue that it is more appropriate to view the problem of generating recommendations as a sequential optimization problem and, consequently, that Markov decision processes (MDPs) provide a more appropriate model for recommender systems. MDPs introduce two benefits: they take into account the long-term effects of each recommendation and the expected value of each recommendation. To succeed in practice, an MDP-based recommender system must employ a strong initial model, must be solvable quickly, and should not consume too much memory. In this paper, we describe our particular MDP model, its initialization using a predictive model, the solution and update algorithm, and its actual performance on a commercial site. We also describe the particular predictive model we used which outperforms previous models. Our system is one of a small number of commercially deployed recommender systems. As far as we know, it is the first to report experimental analysis conducted on a real commercial site. These results validate the commercial value of recommender systems, and in particular, of our MDP-based approach}, url = {http://approjects.co.za/?big=en-us/research/publication/mdp-based-recommender-system/}, edition = {Proceedings of the Eighteenth Conference on Uncertainty in Artificial Intelligence (UAI2002)}, number = {UAI-P-2002-PG-453-460}, note = {Proceedings of Twentieth Conference on Uncertainty in Artificial Intelligence, Banff, Canada, UAI Press}, }