Most of these studies attempt to extract efficient features from text content (Liu and Hsieh, 2006;Lin et al., 2012;Aletras et al., 2016;Sulea et al., 2017) or case annotations (e.g., dates, terms, locations, and types) (Katz et al., 2017).
these conventional methods can only utilize shallow textual features and manually designed factors, both require massive human efforts and usually suffer from the generalization issue when applied to other scenarios.