Information filtering method and apparatus for preferentially taking out information having a high necessity

An adaptive dictionary apparatus with which a keyword effective for judging whether or not information provided from either one of an information recording medium or an information communication network is recorded preferentially into a dictionary, the information including information data and one or more keywords attached to the information data, the apparatus comprising:

• information providing means for providing a user with the information data;
• inputting means for enabling the user to input a signal indicating that the provided information data is necessary or unnecessary;
• learning means for calculating a prediction value for predicting a user's necessity degree of each keyword attached to the provided information data on the basis of the signal inputted by the inputting means;
• and
• dictionary updating means for preferentially registering the keyword effective for the dictionary by using the prediction value.