Abstract: This disclosure relates to a method for providing a recommendation to a recipient. The method comprises obtaining input data, and applying a first mapping to the input data to produce a first primary data representation. The first mapping is a non-bijective mapping. The method comprises providing the first primary data representation and obtaining a second data representation based on the first primary data representation. The method comprises determining recommendation data for the recipient based on the second data representation, and outputting the recommendation data to the recipient.