Patent ID: 7640164

Claim:
A computer system for carrying out an interactive dialog with a user of the computer system in accordance with a predetermined rule, comprising: a data base that stores a dictionary containing a plurality of words and a plurality of phrases; a recognition unit that recognizes a user's input representing what the user says in response to previous output by the computer system in a currently running interactive dialog and understands what the user says from the user's input by referring to the dictionary stored in the data base; a determining unit that determines whether a user error occurs in the user's input, the user error representing that the user's input includes a word or phrase that does not meet the predetermined rule in response to the previous output by the computer system; a selection unit that selects a phrase or word to be used to continue the currently running interactive dialog when the user error occurs in the user's input; and an output unit that outputs the selected phrase or word to the user so as to answer to the user's input, the predetermined rule being defined for a word chain game, the predetermined rule comprising: that the user and the computer system alternate to output a word or phrase which has an initial letter or letters identical with the final letter or letters of the immediately previous output word, the predetermined rule further including: the output word or phrase has not been used since the beginning of each of interactive dialogs including the currently running interactive dialog for the word chain game, and the output word or phrase does not end with particular predetermined letters, the selection unit selects a phrase or word to be used to terminate the currently running interactive dialog irrespective of the determination of whether the user error occurs in the user's input, thus resulting in a user's win in the word chain game, the selected word or phrase having been used since the beginning of the currently running interactive dialog for the word chain game or ending with the particular predetermined letters, wherein, when it is determined that the user error occurs in the user's input, the selection unit estimates an impression of the user's input based on at least one previous interactive dialog for the word chain game, allows the user error based on the estimated impression of the user's input, and selects the phrase or the word to be used to continue the currently running interactive dialog.