A disclosed identification method of identifying a data point distribution area on a coordinate plane includes dividing an area on the coordinate plane into divided areas so that the divided areas radiate from a division center point; selecting, in each of the divided areas, from among the data points in the divided area, a data point having the greatest distance from the division center point as a representative point; determining whether there is an overlapping area where a distribution representative point area overlaps a determination area; and determining, when there is the overlapping area, that the data group to be determined is a relevant data group.