Theories of the coherence of discourse and discourse relations (Barzilay and Lapata, 2005;Byron and Stent, 1998;Hobbs, 1979Hobbs, , 1985Mann and Thompson, 1988;Marcu and Echihabi, 2002) have proved useful for the semantic interpretation of discourse.
in the world of Twitter, Facebook, and other social media where people voluntarily join in the conversation, dialogue is often focused on the social engagements between participants.