1. An information processing method of identifying a class of an object by using a plurality of discriminators, the method comprising: acquiring, as a plurality of candidate classes, a plurality of classes discriminated at a first stage of the discriminators; and setting, in a second stage of the discriminators, a class of the second stage of the discriminators, which is defined as a combined partial space which is formed by combining a first partial space which shows a first range of each of the plurality of candidate classes and a second partial space which shows a second range different from the first range used in discriminating each of the plurality of candidate classes at the first stage of the discriminators, as a class to be discriminated at the second stage of the discriminators, wherein the first range, the second range, and the combined range are in a same discriminating space.