Evaluating the Relative Performance of Collaborative Filtering Recommender Systems
Humberto Jesús Corona Pampín (University College Dublin, Ireland)
Houssem Jerbi (University College Dublin, Ireland)
Michael P. O'Mahony (University College Dublin, Ireland)
Abstract: Past work on the evaluation of recommender systems indicates that collaborative filtering algorithms are accurate and suitable for the top-N recommendation task. Further, the importance of performance beyond accuracy has been recognised in the literature. Here, we present an evaluation framework based on a set of accuracy and beyond accuracy metrics, including a novel metric that captures the uniqueness of a recommendation list. We perform an in-depth evaluation of three well-known collaborative filtering algorithms using three datasets. The results show that the user-based and item-based collaborative filtering algorithms have a high inverse correlation between popularity and diversity and recommend a common set of items at large neighbourhood sizes. The study also finds that the matrix factorisation approach leads to more accurate and diverse recommendations, while being less biased toward popularity.
Keywords: accuracy, beyond accuracy, collaborative filtering, evaluation, matrix factorisation, recommender systems, uniqueness
Categories: H.3.3, H.4, M.5