| 摘要 |
PROBLEM TO BE SOLVED: To limit the range to search for a data part corresponding to a retrieval key by arraying the document information for every group to which the corresponding key item belongs, and retrieving and outputting the document information in response to input of the retrieval key. SOLUTION: The occurrence frequency of the key item of each document stored in a document data base 101 is obtained via the actions of a word detection means 111 and a count means 113. Accordingly, a 1st sort means 114 sorts the key items and an array means 115 changes the array of the document information held at a document information holding part 112 based on the sort result of key items. Thus, the distribution range of the means 112 can be limited for the document information corresponding to the key items of similar occurrence frequency. Then a retrieval means 116 can limit the searching range of the means 112 for the desired document information by controlling the distribution range of document information in response to the occurrence frequency of key items. |
