Nested Named Entity Recognition via Second-best Sequence Learning and Decoding
Table 8: Comparison on ACE-2004. “†” indicates the methods using POS tags.
['[BOLD] Method', 'P (%)', 'R (%)', 'F1 (%)']
We compare our method with existing methods also on the ACE-2004 dataset. We use the same splits as Lu and Roth The setups are the same as those of our experiment on ACE-2005. As shown, our method significantly outperforms existing methods. Note that most of them use POS tags as an additional input feature whereas our method does not.