Parsing to Noncrossing Dependency Graphs

• Published in: Transactions of the Association for Computational Linguistics Vol. 3; pp. 559 - 570
• Main Authors: Kuhlmann, Marco, Jonsson, Peter
• Format: Journal Article
• Language: English
• Published: One Rogers Street, Cambridge, MA 02142-1209, USA MIT Press 2015; MIT Press Journals, The
• Subjects: Algorithms; complexity theory; Computational linguistics; Generalization; Graph theory; Graphs; Inference; natural language processing; Optimization; Parsing; Semantics
• ISSN: 2307-387X; 2307-387X
• DOI: 10.1162/tacl_a_00158

We study the generalization of maximum spanning tree dependency parsing to
maximum acyclic subgraphs. Because the underlying optimization problem is
intractable even under an arc-factored model, we consider the restriction to
dependency graphs. Our main
contribution is a cubic-time exact inference algorithm for this class. We extend
this algorithm into a practical parser and evaluate its performance on four
linguistic data sets used in semantic dependency parsing. We also explore a
generalization of our parsing framework to dependency graphs with
and show that the resulting
optimization problem is NP-hard for
≥ 2.