Especially through many neural network methods used for this task such as convolutional neural network (CNN) (Qin et al., 2016b), recursive neural network (Ji and Eisenstein, 2015), embedding improvement , attention mechanism (Liu and Li, 2016), gate mechanism , multi-task method (Lan et al., 2017), the performance of this task has improved a lot since it was first introduced.
this task is still very challenging with the highest reported accuracy still lower than 50% due to the hardness for the machines to understand the text meaning and the relatively small task corpus.