Amazon at MRP 2019: Parsing Meaning Representations with Lexical and Phrasal Anchoring

摘要

This paper describes the system submission of our team Amazon to the shared task on Cross Framework Meaning Representation Parsing (MRP) at the 2019 Conference for Computational Language Learning (CoNLL). Via extensive analysis of implicit alignments in AMR, we recategorize five meaning representations (MRs) into two classes: Lexical-Anchoring and Phrasal-Anchoring. Then we propose a unified graph-based parsing framework for the lexical-anchoring MRs, and a phrase-structure parsing for one of the phrasal-anchoring MRs, UCCA. Our system submission ranked 1st in the AMR subtask, and later improvements shows promising results on other frameworks as well.