1. A method for ranking a data set of objects comprising: providing a graph representing the data set; providing examples of ranking preferences for a portion of objects in the data set, each of said examples identifying a pair of objects of the portion, the pair of objects indicating a ranking preference of a first object of the pair with respect to the second object of the pair, said each example indicating that the first object of the pair is ranked higher than the second object of the pair, wherein penalty values are specified for said examples, one of said penalty values being specified for each of said examples wherein the one of the penalty values for said each example indicates a penalty value for improperly ordering the pair of objects of said each example, a first of the penalty values for a first of said examples specifying a first value that is different than a second value specified as a second of the penalty values for a second of said examples, wherein an allowable value for each of the penalty values includes any real value; determining, using inputs including said examples and the penalty values specified for said examples, a function, f, that ranks the objects of the data set; and determining a ranking of the objects of the data set using said function, f, wherein at least one of said providing a graph, said providing examples, said determining a function and said determining a ranking are performed using a processor.