Document clustering system, document clustering method, and recording medium

A document clustering method that is performed by a clustering system for sorting a collection of a plurality of documents into document clusters and comprising:

• a concept tree structure acquisition step that acquires a concept tree structure that represents the hierarchical relationship of a concept of a plurality of words;
• a document set acquisition step that acquires a document set, which is a collection of documents;
• a concept similarity computation step that finds the concept similarity between two arbitrary words of the document set that was acquired by the document set acquisition step, the concept similarity being an index indicating the closeness of the two words in a concept;
• an inter-document similarity computation step that finds inter-document similarity, which is the degree of semantic similarity between two documents that are included in the document set that was acquired by the document set acquisition step, based on the concept similarity found by the concept similarity computation step;
• and
• a clustering step that performs document clustering of the document set based on the inter-document similarity that was found by the inter-document similarity computation step.

A recording medium that can be read by a computer and stores a program that causes a computer to execute:

• a concept tree structure acquisition step that acquires a concept tree structure that represents the hierarchical relationship of a concept of a plurality of words;
• a document set acquisition step that acquires a document set, which is a collection of documents;
• a concept similarity computation step that finds the concept similarity between two arbitrary words of the document set that was acquired by the document set acquisition step, the concept similarity being an index indicating the closeness of the two words in a concept;
• an inter-document similarity computation step that finds inter-document similarity, which is the degree of semantic similarity between two documents that are included in the document set that was acquired by the document set acquisition step, based on the concept similarity found by the concept similarity computation step;
• and
• a clustering step that performs document clustering of the document set based on the inter-document similarity that was found by the inter-document similarity computation step.