Abstract
It is important to clarify referents of nouns in machine translation and conversational processing. We present a method for estimating referents of nouns in Japanese sentences using referential properties, modifiers, and owners of nouns. Since there is no article in Japanese language, it is difficult to decide whether two nouns have the same referent in Japanese. To solve this difficult problem, we had made a research to estimate referential properties of nouns that correspond to articles using words in the sentences, and we estimate referents of nouns using these referential properties. For example if the referential property of a noun is definite, the noun can refer to nouns that appear ahead, and if the referential property of a noun is indefinite, the noun can not refer to nouns that appear ahead. Furthermore we estimate referents of nouns using modifiers and owners of nouns more precisely. As a result, we obtained a precision rate of 82% and a recall rate of 85% in the estimation of referent of nouns that have antecedents on training sentences, and obtained a precision rate of 79% and a recall rate of 77% on held-out test sentences. We verified that it is effective to use referential properties, modifiers, and owners of nouns through control experiments.
