First, all previous systems were evaluated on the same set of 38 documents that initially contains 991 sentences -and more precisely on each sentence of this set for intra-sentential results.
soricut and Marcu (2003) do not consider sentences that are not exactly spanned by a discourse subtree (keeping only 941 sentences in the test set), and sporleder and Lapata (2005) only keep the sentences that contain intra-sentential EDUs (608 sentences).