Without these resources, researchers have resorted to developing their own small, ad hoc datasets (Barzilay and McKeown, 2001;Shinyama et al., 2002;Barzilay and Lee, 2003;, and have often relied on human judgments to evaluate their results (Barzilay and McKeown, 2001;Ibrahim et al., 2003;Bannard and Callison-Burch, 2005).
the data thus has some similarities to parallel news descriptions of the same event, while avoiding much of the noise inherent in news.