), each of which involves different assumptions about and models of various linguistic phenomena (e.g., vocabulary, syntax, and semantics).
state-of-theart systems yield varying performance across subproblems (Mitkov, 2014;Kummerfeld and Klein, 2013;Björkelund and Nugues, 2011;Recasens and Hovy, 2009;Stoyanov et al., 2009;Bengtson and Roth, 2008;Van Deemter and Kibble, 2000;Ng and Cardie, 2002b;Kameyama, 1997).