Constituency Structure over Eojeol in Korean Treebanks
This work solves a fundamental representational issue for Korean NLP researchers by enabling cross-treebank comparison and constituency-dependency conversion.
This paper addresses the representational problem of choosing terminal units in Korean constituency treebanks by proposing an eojeol-based constituency representation, showing that under explicit normalization assumptions, the Sejong and Penn Korean treebanks can be treated as representationally equivalent at this level.
The design of Korean constituency treebanks raises a fundamental representational question concerning the choice of terminal units. Although Korean words are morphologically complex, treating morphemes as constituency terminals conflates word internal morphology with phrase level syntactic structure and creates mismatches with eojeol based dependency resources. This paper argues for an eojeol based constituency representation, with morphological segmentation and fine grained part of speech information encoded in a separate, non constituent layer. A comparative analysis shows that, under explicit normalization assumptions, the Sejong and Penn Korean treebanks can be treated as representationally equivalent at the eojeol based constituency level. Building on this result, we outline an eojeol based annotation scheme that preserves interpretable constituency and supports cross treebank comparison and constituency dependency conversion.