Then, aggregation methods can also be applied to summarization to combine multiple ranking results into an aggregation ranking to generate the combined results.
table 1 shows the comparison results (F-measure) on DUC2004 data set in ROUGE-1, ROUGE-2 and ROUGE-SU4 along with corresponding 95% confidence intervals and Figure 2 gives an illustration of the comparison on ROUGE-1 metric (LexPR is short for LexPageRank shown in the figure).