On the one hand, the presence of numerous sources conveying the same information causes difficulties for end users of search engines and news providers; they must read the same information over and over again.
redundancy can be exploited to identify important and accurate information for applications such as summarization and question answering (Mani and Bloedorn 1997;Radev and McKeown 1998;Radev, Prager, and Samn 2000;Clarke, Cormack, and Lynam 2001;Dumais et al.