Document Characteristic Analysis Device for Document To Be Surveyed

摘要

An index term extraction device including: input means ( 1 ) for inputting a document-to-be-surveyed d and documents-to-be-compared P; index term extraction means ( 120 ) for extracting an index term from the document-to-be-surveyed d; first appearance frequency calculation means ( 142 ) for calculating a function value IDF (P) of the appearance frequency of the extracted index term in the documents-to-be-compared P; similar documents selecting means ( 160 ) for selecting similar documents S similar to the document-to-be-surveyed d in the documents-to-be-compared P according to the data on the document-to-be-surveyed d; second appearance frequency calculation means ( 171 ) for calculating the function value IDF (S) of the appearance frequency of the extracted index term in the similar documents S; and output means ( 4 ) for outputting each index term and its positioning data according to the combination of the function values of the respective appearance frequencies in the documents-to-be-compared and the similar documents which have been calculated. Thus, it is possible to accurately grasp the feature of the document-to-be-surveyed.