Similar document retrieval method using plural similarity calculation methods and recommended article notification service system using similar document retrieval method

A similar document retrieval method capable of realizing an improved retrieval performance. In this similar document retrieval method for retrieving similar documents of a reference document from a plurality of retrieval target documents, similarities of each one of the plurality of retrieval target documents with respect to the reference document are calculated by using each one of two or more similarity calculation methods separately, and the similar documents of the reference document are retrieved by carrying out a discrimination analysis with respect to each one of a plurality of similarities calculated by using each one of the two or more similarity calculation methods separately.