The Great Importance of Cross-Document Relationships for Multi-document Summarization

摘要

Graph-based methods have been developed for multi-document summarization in recent years and they make use of the relationships between sentences in a graph-based ranking algorithm to extract salient sentences. This paper proposes to differentiate the cross-document relationships and the within-document relationships between sentences for multi-document summarization. The two kinds of relationships between sentences are deemed to have unequal contributions in the graph-based ranking algorithm. We apply the graph-based ranking algorithm based on each kind of sentence relationships and explore their relative importance for multi-document summarization. Experimental results on DUC 2002 and DUC 2004 data demonstrate the great importance of the cross-document relationships between sentences for multi-document summarization. Even the system based only on the cross-document relation-ships can perform better than or at least as well as the systems based on both kinds of relationships between sentences.