PURPOSE: To unnecessitate the swinging table of a notation with a large amount of items, and to unnecessitate the preparing and editing operation by operating a dictionary retrieval from a derivative to which a swinging regulation is applied for the notation input of the dictionary retrieval.

CONSTITUTION: When the same notation is absent in a word index dictionary 2, an editor 3 refers to a notation swinging regulation 3A, extracts a rule corresponding to the input notation, obtains the notation (derivative) obtained by rewriting the input notation according to the regulation having the pertinent rule, checks whether or not the derivative is registered in the word index dictionary 2, reads the term of the notation from an actual dictionary 1 when the pertinent derivative is registered in the dictionary 2, and outputs it to a man/ machine interface 4. At the time of the output, the editor 3 outputs a message such as 'this word may be equivalent to the swinging of a word * * *'which means the application of the swinging regulation. Then, a user can correct the input data for the swinging used on the same judgement reference by the message.