First, the pair-wise classifier approaches learn a classifier on mention pairs (edges) (Soon et al., 2001;Ng and Cardie, 2002;Bengtson and Roth, 2008), and perform some form of approximate decoding or post-processing using the pair-wise scores to make predictions.
the pair-wise classifier approach suffers from several drawbacks including class imbalance (fewer positive edges compared to negative edges) and not being able to leverage the global structure (instead making independent local decisions).