A Hierarchical Unification of LIRICS and VerbNet Semantic Roles

Abstract

This research compares several of the thematic roles of Verb Net (VN) to those of the Linguistic Infrastructure for Interoperable Resources and Systems (LIRICS). The purpose of this comparison is to develop a standard set of thematic roles that would be suited to a variety of natural language processing (NLP) applications. We draw from both resources to construct a unified set of semantic roles that will replace existing VN semantic roles. Through the process of comparison, we find that a hierarchical organization of coarse-grained, intermediate and fine-grained roles facilitates mapping between semantic resources of differing granularity and allows for flexibility in how VN can be used for diverse NLP applications, thus, we propose a hierarchical taxonomy of the unified role set. The comparison and subsequent development of the hierarchy reveals a level of granularity shared by both resources, which could be further developed into a standard set of thematic roles for the International Organization for Standardization (ISO).