6. A document recommendation system comprising: a set of positive documents determined to be of interest to a user; a set of negative documents determined to not be of interest to the user; a plurality of candidate documents; and a module configured to calculate similarity scores of each document in the set of positive documents relative to the plurality of candidate documents and to calculate similarity scores of each document in the set of negative documents relative to the plurality of candidate documents, and wherein the module receives a new document apart from the plurality of candidate documents, calculates a similarity score, using a processor, of the new document relative to each of the plurality of candidate documents using a measure of discriminatively trained similarity associated with each of the plurality of candidate documents, and outputs a reference to at least one of the plurality of candidate documents based on the calculated similarity scores.
6. A document recommendation system comprising: a set of positive documents determined to be of interest to a user; a set of negative documents determined to not be of interest to the user; a plurality of candidate documents; and a module configured to calculate similarity scores of each document in the set of positive documents relative to the plurality of candidate documents and to calculate similarity scores of each document in the set of negative documents relative to the plurality of candidate documents, and wherein the module receives a new document apart from the plurality of candidate documents, calculates a similarity score, using a processor, of the new document relative to each of the plurality of candidate documents using a measure of discriminatively trained similarity associated with each of the plurality of candidate documents, and outputs a reference to at least one of the plurality of candidate documents based on the calculated similarity scores. 7. The document recommendation system of claim 6 , wherein the new document comprises at least one of an audio, video, and image data.