Constraints and defaults on zero pronouns in Japanese instruction manuals

Abstract

In this paper, we propose a method for anaphora resolution of zero subjects in Japanese manual sentences based on both the nature of language expressions and the ontology of ordinary instruction manuals. In instruction manuals written in Japanese, zero subjects often introduce ambiguity into sentences. In order to resolve them, we consider the property of several types of expressions including some forms of verbal phrases and some conjunctives of clauses, and so on. As the result, we have a set of constraints and defaults for zero subject resolution. We examine the precision of the constraints and defaults with real manual sentences, and we have the result that they make a good estimate with precision of over 80%.