Abstract: An information processing apparatus deletes specific types of characters from each of multiple sentences and generates multiple word strings which do not include the specific types of characters and correspond to the multiple sentences. The information processing apparatus divides the multiple word strings into multiple groups, each including two or more word strings. The information processing apparatus performs, for each of the multiple groups, padding to equalize the number of words among the two or more word strings based on the maximum number of words in the two or more word strings. The information processing apparatus updates, using each of the multiple padded groups, parameter values included in a natural language processing model that calculates an estimate value from a word string input thereto.