GENERALIZING HIERARCHY SET GENERATION DEVICE, GENERALIZING HIERARCHY SET GENERATION METHOD, AND PROGRAM

摘要

Provided is a technology that generates a set of generalizing hierarchies that reduce information loss when generalizing arbitrary data that does not necessarily have a numerical meaning. The technology includes a second generation unit that generates a second generalization hierarchy set that fulfils prescribed properties, for a data set to be generalized and for a generalizing hierarchy set (the generalizing hierarchy set including, as at least one element thereof, a generalizing hierarchy that includes arbitrary data to be generalized that is included in the data set to be generalized). When M is the maximum value for the length of a generalizing hierarchy included in the generalizing hierarchy set, D is a prescribed integer of 1–M, and D' is a prescribed integer of D–M, the second generalizing hierarchy set fulfills the properties of: data in layer d (0 ≦ d ≦ D – 1) in the generalizing hierarchy being the same data; the length of the generalizing hierarchy being D'; and the data in layer D'–1 being an element of the data set to be generalized.