The approaches are studied in (Bakliwal et al., 2011;Bespalv et al., 2011;Kennedy and Inkpen, 2006;Jin et al., 2009;Narayanan et al., 2009;Pang et al., 2002;Schuller and Knaup, 2011).
the lexicon-based approaches are mostly unsupervised, requiring a dictionary or a lexicon of pretagged words.