Acquiring Reliable Predicate-argument Structures from Raw Corpora for Case Frame Compilation

AbstractWe present a method for acquiring reliable predicate-argument structures from raw corpora for automatic compilation of case frames. Such lexicon compilation requires highly reliable predicate-argument structures to practically contribute to Natural Language Processing (NLP) applications, such as paraphrasing, text entailment, and machine translation. However, to precisely identify predicate-argument structures, case frames are required. This issue is similar to the question ""what came first: the chicken or the egg?"" In this paper, we propose the first step in the extraction of reliable predicate-argument structures without using case frames. We first apply chunking to raw corpora and then extract reliable chunks to ensure that high-quality predicate-argument structures are obtained from the chunks. We conducted experiments to confirm the effectiveness of our approach. We successfully extracted reliable chunks of an accuracy of 98% and high-quality predicate-argument structures of an accuracy of 97%. Our experiments confirmed that we succeeded in acquiring highly reliable predicate-argument structures that can be used to compile case frames.