Because documents have pre-defined structures (e.g., sections, paragraphs, sentences) for different levels of concepts in a hierarchy, most recent summarization work has focused on structured probabilistic models to represent the corpus concepts (Barzilay et al., 1999;Daumé-III and Marcu, 2006;Eisenstein and Barzilay, 2008;Tang et al., 2009;Chen et al., 2000;Wang et al., 2009).
(Haghighi and Vanderwende, 2009;Celikyilmaz and Hakkani-Tur, 2010) build hierarchical topic models to identify salient sentences that contain abstract concepts rather than specific concepts.