Taxonomy of Fine-grain Semantic Roles for Nominal Modifiers

To assign semantic roles in building Treebanks, there is a need for annotators having a guideline in determining semantic relations between phrasal head and its modifiers or arguments. Semantic roles are hard to have clear-cut definitions. It is not always easy to determine thematic relations between two concepts. This paper aims to introduce an integrated nominal modifier system. Basically we adopt other scholars' incisive idea in analyzing semantic roles that modify general nouns. We use the approach of building a fine-grain taxonomy of role system. The taxonomy of fine-grain thematic roles makes the role determination easier for human annotators, since the meaning of a fine-grain semantic role is self explanatory and a higher-level semantic role is described by its hyponyms. The proposed taxonomy has been attested during construction of Sinica TreeBank and HowNet definitions of nominal concepts and proven to be more applicable than conventional flat structures.