Compilation of an idiom example database for supervised idiom identification

Some phrases can be interpreted in their context either idiomatically (figuratively) or literally. The precise identification of idioms is essential in order to achieve full-fledged natural language processing. Because of this, the authors of this paper have created an idiom corpus for Japanese. This paper reports on the corpus itself and the results of an idiom identification experiment conducted using the corpus. The corpus targeted 146 ambiguous idioms, and consists of 102,856 examples, each of which is annotated with a literal/idiomatic label. All sentences were collected from the World Wide Web. For idiom identification, 90 out of the 146 idioms were targeted and a word sense disambiguation (WSD) method was adopted using both common WSD features and idiom-specific features. The corpus and the experiment are both, as far as can be determined, the largest of their kinds. It was discovered that a standard supervised WSD method works well for idiom identification and it achieved accuracy levels of 89.25 and 88.86%, with and without idiom-specific features, respectively. It was also found that the most effective idiom-specific feature is the one that involves the adjacency of idiom constituents.