Abstract: A keyword assigning system divides text data into words, stores results of the division in a table, detects numbers of occurrence times of words in each text data, registers them in a table, and obtains word occurrence frequencies in domains on the basis of the table. The system then extract keywords from the text data by domain on the basis of a resulted domain-wise word occurrence collection table, and extracts negligible word not capable of becoming keywords by domain. The system further registers the extracted domain-wise keywords and negligible words in a keyword-negligible word dictionary, looks the keywords and negligible words registered in the dictionary upon assignment of the keywords to the text data to extract words to become keywords from among the words of the text data to have the keywords assigned thereto, and assign the extracted keywords to the text data, thereby automatically making extraction and assignment of most of the keywords.

Abstract: A text retrieval method and a text retrieval apparatus for retrieving texts based on a handwritten keyword inputted from an optical character reader are provided. Respective characters of a keyword string are recognized by character recognizing device, and recognized characters of respective characters are stored in a recognized character table. At least one recognized character is extracted as proposed recognized characters of respective characters from recognized characters stored in the recognized character table, and a plurality of character strings are generated by combining one proposed character among proposed recognized characters of respective characters with one another and stored in a keyword string table. A retrieval command string for retrieving texts including at least one character string among generated character strings out of a text database is generated, and the text database is retrieved by the retrieval command, thus obtaining a retrieved result.

Abstract: A system for changing a natural language sentence input by a user. The sentence expresses an operation specification which is translated to an operation specification command in a machine language for an operation specification object such as database. The system has a function to define specific items necessary for changing the natural language input sentence to the operation specification command without forcing the user to decide complicated definitions related to the operation specification object. The system refers to an operation specification object information table which stores at least one of the following acquired from the user:(1) A unit word or an interrogative word (phrase) with respect to each of the items in the database;(2) An explanatory sentence with respect to each of the items in the database; and(3) An item pair which is specifiable as a join condition of each of the items in the database.