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Semi-supervised conditional random fields for improved sequence segmentation and labeling

Published 1 January 2006Open access
Feng Jiao, Shaojun Wang, Chi‐Hoon Lee, Russell Greiner, Dale Schuurmans
Citations130
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TL;DR

A new semi-supervised training procedure for conditional random fields (CRFs) that can be used to train sequence segmentors and labelers from a combination of labeled and unlabeled training data is presented, based on extending the minimum entropy regularization framework to the structured prediction case.

Abstract

We present a new semi-supervised training procedure for conditional random fields (CRFs) that can be used to train sequence segmentors and labelers from a combination of labeled and unlabeled training data. Our approach is based on extending the minimum entropy regularization framework to the structured prediction case, yielding a training objective that combines unlabeled conditional entropy with labeled conditional likelihood. Although the training objective is no longer concave, it can still be used to improve an initial model (e.g. obtained from supervised training) by iterative ascent. We apply our new training algorithm to the problem of identifying gene and protein mentions in biological texts, and show that incorporating unlabeled data improves the performance of the supervised CRF in this case.

Keywords

Computer ScienceBiochemistry, Genetics and Molecular Biology