optimizing multiple objectives in collaborative filtering
This paper is about the utility of making personalized recommendations. While it is important to accurately predict the target user's preference, in practice the accuracy should not be the only concern ; a useful recommender system needs to consider the user's utility or satisfaction of fulfilling a certain information seeking task. For example, recommending popular items (products) is unlikely to result in more gain than discovering insignificant ("long tail") yet liked items because the popular ones might be already known to the user. Equally, recommending items that are out of stock would be frustrating for both the user and system if the system is employed to discover items to purchase. Thus, it is important to have a flexible recommendation framework that takes into account additional recommendation goals meanwhile minimizing the performance loss in order to provide greater adjustability and a better user experience. To achieve this, in this paper, we propose a general recommendation optimization framework that not only considers the predicted preference scores (e.g. ratings) but also deals with additional operational or resource related recommendation goals. Using this framework we demonstrate through realistic examples how to expand existing rating prediction algorithms by biasing the recommendation depending on other external factors such as the availability, profitability or usefulness of an item. Our experiments on real data sets demonstrate that this framework is indeed able to cope with multiple objectives with minor performance loss.
multiple objectives collaborative filtering personalization recommender systems popularity long tail stock management