Efficient Staggered Decoding for Sequence Labeling

The Viterbi algorithm is the conventional decoding algorithm most widely adopted for sequence labeling. Viterbi decoding is, however, prohibitively slow when the label set is large, because its time complexity is quadratic in the number of labels. This paper proposes an exact decoding algorithm that overcomes this problem. A novel property of our algorithm is that it efficiently reduces the labels to be decoded, while still allowing us to check the optimality of the solution. Experiments on three tasks (POS tagging, joint POS tagging and chunking, and supertagging) show that the new algorithm is several orders of magnitude faster than the basic Viterbi and a state-of-the-art algorithm, CARPEDIEM (Esposito and Radicioni, 2009).

• Type: Journal
• Year: 2010
• Where: ACL
• Authors: Nobuhiro Kaji, Yasuhiro Fujiwara, Naoki Yoshinaga, Masaru Kitsuregawa
• Keywords: ACL 2010, Algorithm, Computational Linguistics, Exact Decoding Algorithm, Labels