Table 4 shows a comparison of existing and proposed summarization systems on the set of corpora in §5 except for Newsroom 12 .
lin and Bilmes (2011) claim that many existing summarization systems are instances of mixtures of such sub-aspect functions; for example, maximum marginal relevance (MMR) (Carbonell and Goldstein, 1998) can be seen as an combination of diversity and importance functions.