1. An apparatus for controlling a recommender system, said apparatus comprising: a) a feature-value extractor ( 116 ) for analyzing a user profile ( 109 ) and for extracting feature-value pairs which characterize a user of said recommender system; b) a query composer ( 118 ) for composing based on feature-value pairs extracted by said feature-value extractor ( 116 ) a query to be sent to at least one content source ( 103 ); and c) a recommender engine ( 107 ) for rating results obtained in response to said query so as to provide a recommendation for said user, said apparatus being characterized in that it further comprises a feature selector ( 117 ) for selecting from said feature-value pairs extracted by said feature-value extractor ( 116 ) those feature-value pairs which are most discriminative for said user profile ( 109 ), wherein the feature selector ( 117 ) is adapted to use the Relief algorithm as a feature selection algorithm for selecting said most discriminative feature-value pairs.