On Dual Decomposition and Linear Programming Relaxations for Natural Language Processing

This paper introduces dual decomposition as a framework for deriving inference algorithms for NLP problems. The approach relies on standard dynamic-programming algorithms as oracle solvers for sub-problems, together with a simple method for forcing agreement between the different oracles. The approach provably solves a linear programming (LP) relaxation of the global inference problem. It leads to algorithms that are simple, in that they use existing decoding algorithms; efficient, in that they avoid exact algorithms for the full model; and often exact, in that empirically they often recover the correct solution in spite of using an LP relaxation. We give experimental results on two problems: 1) the combination of two lexicalized parsing models; and 2) the combination of a lexicalized parsing model and a trigram part-of-speech tagger.

• Type: Journal
• Year: 2010
• Where: EMNLP
• Authors: Alexander M. Rush, David Sontag, Michael Collins, Tommi Jaakkola
• Keywords: Algorithms, EMNLP 2010, Lexicalized Parsing, Natural Language Processing, Standard Dynamic-programming Algorithms