... sen-tence, G: Gold standard, D: Decision-tree, LM: IPlanguage model, Sig: IP language model with sig-nificance score)Model CompR RatingDecision-tree 56.1% 2.22∗†LangModel 49.0% 2.23∗†LangModel+Significance ... (Vandeghinste andPan 2004) and information retrieval (Olivers andDolan 1999). Sentence compression is a complexparaphrasing task with information loss involv-ing substitution, deletion, insertion, and ... original sentences and theircompressions.Unsupervised approaches to the compressionproblem are few and far between (see Hori and Fu-rui 2004 and Turner and Charniak 2005 for excep-tions)....