The First Shared Task on Discourse Representation Structure Parsing
This addresses the challenge of semantic parsing for NLP researchers, though it is incremental as it builds on existing DRS frameworks.
The paper presents the IWCS 2019 shared task on Discourse Representation Structure (DRS) parsing for English sentences, which involves producing scoped semantic representations with lexical and thematic information. The results showed improvements over the existing state-of-the-art parser.
The paper presents the IWCS 2019 shared task on semantic parsing where the goal is to produce Discourse Representation Structures (DRSs) for English sentences. DRSs originate from Discourse Representation Theory and represent scoped meaning representations that capture the semantics of negation, modals, quantification, and presupposition triggers. Additionally, concepts and event-participants in DRSs are described with WordNet synsets and the thematic roles from VerbNet. To measure similarity between two DRSs, they are represented in a clausal form, i.e. as a set of tuples. Participant systems were expected to produce DRSs in this clausal form. Taking into account the rich lexical information, explicit scope marking, a high number of shared variables among clauses, and highly-constrained format of valid DRSs, all these makes the DRS parsing a challenging NLP task. The results of the shared task displayed improvements over the existing state-of-the-art parser.