Abstract
This paper deals with Japanese riddles that are created using not only different meanings of two homonymous verbs but also common knowledge of causal relation, and aims at the construction of a creation system of such Japanese riddles. The proposed system consists of a creation part and two kinds of databases. The one database has information on verbs, their use frequency and the case relation between verbs and noun phrases. The other has information on effects caused by the action expressed by a verb and the degree of causal relation between actions and effects. From these sorts of databases the creation part extracts homonymous verbs and noun phrases having case relations to extracted verbs using the following indices; the verb's use frequency and the degree of causal relations. And then the creation part chooses one homonym occurring to human easily among chosen homonyms, and creates as interesting Japanese riddles as the ones that human does. The creation part also shows their answers with explanations. This paper also shows subject experiments in order to confirm whether interesting riddles are created by the presented system.
