🤖 AI Summary
Korean phrase-structure treebanks have long faced a terminal-unit selection dilemma: using morphemes as terminals conflates intra-word morphology with syntactic structure and impedes alignment with eojeol-based dependency treebanks. This paper proposes a phrase-structure representation with eojeol (orthographic word) as the terminal unit. We formally establish, for the first time, phrase-structure equivalence between the Sejong and Penn Korean treebanks at the eojeol level. We design a two-tier annotation framework: an upper tier encoding pure syntactic constituency, and a lower tier independently representing morphological and part-of-speech information. Additionally, we introduce an explicit constituency–dependency mapping model. Our approach achieves strict decoupling of syntax and morphology, enabling unified cross-treebank representation, high-fidelity parsing, paradigm conversion (e.g., constituency ↔ dependency), and joint modeling across heterogeneous linguistic resources.
📝 Abstract
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.