“…Based on the differences in their story representations, we distinguish between three types of TTM tracking methods: (a) keyword representation, (b) group representation, and (c) combo representation methods. Type (a) methods use a list of bursty n-grams ranked by their burst scores (Kleinberg, 2002;Fung, Yu, Yu, & Lu, 2005;Gruhl, Guha, Kumar, Novak, & Tomkins, 2005;He, Chang, Lim, & Zhang, 2007;Smith, 2002). Type (b) methods assemble bursty n-grams into groups which point to subjects (Fung et al, 2005;Wang & McCallum, 2006;Mei & Zhai, 2005;Schult & Spiliopoulou, 2006;Janssens, Glänzel, & Moor, 2007).…”