1. A computer-implemented method for generating a plurality of groups, each including at least one of a plurality of elements, the method comprising the steps of: selecting, by the computer, at least one candidate element from the plurality of elements as a candidate to be included in a group; determining, by the computer, whether or not to generate the group including the at least one candidate element selected in the selecting step, based on an element evaluation value associated with each of the at least one candidate element selected in the selecting step; provided that a determination is made to generate the group in the determining step, generating, by the computer, the group including the at least one candidate element selected in the selecting step; and weighting, by the computer, the element evaluation value of each of the at least one element according to how many times the each element is included in already-generated groups, so as to reflect the weighted element evaluation value in next group generation.