Abstract: An information processing apparatus includes a processor. The processor is programmed to output, by performing clustering on vocabulary information, vocabulary classification information representing a classification of an existing ontology that is systematically represented by linking plural concepts. The vocabulary information is produced from text information not classified into the existing ontology. The vocabulary information represents a semantic correlation of a vocabulary. The clustering uses concept classification information that is produced in accordance with an inheritance relation between the concepts included in the existing ontology and that is indicated as a pair of a concept as an inheritance source and a concept as an inheritance destination. The processor is programmed to then extend the existing ontology by adding to the existing ontology a concept absent in the existing ontology by using the vocabulary classification information.