1. A method for efficiently identifying images, videos, audio files or documents relevant to a user, the method comprising: determining a set of ranking functions, each of which predicts or assigns a relative strength of an attribute in an image, video, audio file or document from a pool of database images, videos, audio files or documents; presenting a set of reference images, videos, audio files or documents from said pool of database images, videos, audio files or documents; receiving a selection of one or more images, videos, audio files or documents from said set of reference images, videos, audio files or documents along with relative attribute feedback pertaining to one or more attributes of said selected one or more images, videos, audio files or documents; and revising, by a processor, a system's model of what images, videos, audio files or documents are relevant to said user using said relative attribute feedback.