Instead of reading a long list of reviews, customers usually are only willing to view a handful of helpful reviews to make their purchase decisions.
helpful reviews have even greater influences on the potential customers' decision-making processes and thus on the sales; as a result, the automatic identification of helpful reviews has received considerable research attentions in recent years (Kim et al., 2006;Liu et al., 2008;Mudambi, 2010;Xiong and Litman, 2014;Martin and Pu, 2014;Yang et al., 2015.