Turbo Parsers: Dependency Parsing by Approximate Variational Inference

We present a unified view of two state-of-theart non-projective dependency parsers, both approximate: the loopy belief propagation parser of Smith and Eisner (2008) and the relaxed linear program of Martins et al. (2009). By representing the model assumptions with a factor graph, we shed light on the optimization problems tackled in each method. We also propose a new aggressive online algorithm to learn the model parameters, which makes use of the underlying variational representation. The algorithm does not require a learning rate parameter and provides a single framework for a wide family of convex loss functions, including CRFs and structured SVMs. Experiments show state-of-the-art performance for 14 languages.

• Type: Journal
• Year: 2010
• Where: EMNLP
• Authors: André F. T. Martins, Noah A. Smith, Eric P. Xing, Pedro M. Q. Aguiar, Mário A. T. Figueiredo
• Keywords: EMNLP 2010, Loopy Belief Propagation, Natural Language Processing, Non-projective Dependency Parsers, Relaxed Linear Program