摘要 |
Processing for a time-series analysis of keywords comprises clustering or classifying pieces of document data, each of which is description of a phenomenon in a natural language, on the basis of frequencies of occurrence of keywords in the pieces of document data, individual keywords being also clustered or classified by clustering or classifying the pieces of document data, and performing a time-series analysis of frequencies of occurrence of pieces of document data containing individual keywords in clusters or classes into which the pieces of document data are clustered or classified or a time-series analysis of frequencies of occurrence of pieces of document data containing clusters or classes into which the individual keywords are clustered or classified. Frequency distribution showing variation of the frequencies of occurrence of the pieces of document data is acquired by the time-series analysis. |