CLUSTER ANALYSIS METHOD, CLUSTER ANALYSIS SYSTEM, AND CLUSTER ANALYSIS PROGRAM

A server 4 executes a similarity calculation step (S2) of calculating similarity between content of one document and content of another document, a cluster classification step (S3) of generating a network in which a document is set as a node based on calculated similarity and similar nodes are connected by an edge, and performing classification based on similar documents, a first index calculation step (S4) of calculating a first index indicating centrality of a document in the network, a second index calculation step (S5) of calculating a second index that is different from the first index in the network and indicates importance of a document, and a display data generation step (S6) of generating, regarding a document, first display data indicating the network by an expression of a size of an object of a node according to the first index, an expression of a gauge having a shape corresponding to a shape of the object according to the second index and a length of the gauge, an expression according to a type of the cluster, and an expression according to magnitude of similarity between documents.