Several studies have demonstrated that the use of unlabeled data can improve the performance of NLP tasks, such as text chunking (Ando and Zhang, 2005), POS tagging and named entity recognition (Suzuki and Isozaki, 2008), and parsing (Suzuki et al., 2009;Chen et al., 2009;Koo et al., 2008).
it is attractive to consider adopting semi-supervised learning in Chinese word segmentation and POS tagging tasks.