Abstract: Mitigation of noise in vector space representations of item collections for applications such as facial recognition and spam detection. After receiving a collection of items, each item characterized by a plurality of features, a first vector space representative of the collection is prepared. Each item in the first vector space is represented by a vector that is a function of the features characterizing the item. Based on information characteristic of the first vector space, at least one of items contributing to first vector space noise, and features contributing to first vector space noise are identified. The first identified items and features are weighted to decrease the influence of the first identified items and features on vector spaces representative of the collection. A second vector space representative of the collection is prepared based on the first weighted items and features.