Discourse Level Factors for Sentence Deletion in Text Simplification
Table 4: Depth distribution of sentences in RST trees. Deleted sentences are located significantly (p<0.05) lower than the ones that are kept, using the Wilcoxon ranked test [Wilcoxon1992].
['[EMPTY]', 'Middle Kept', 'Middle Deleted', 'Elementary Kept', 'Elementary Deleted']
We observe that sentences that are deleted locate at significantly lower levels in their discourse trees comparing to those that are kept. Since salient sentences tend to locate closer to the root of the discourse tree, this indicates that salience plays some role in the decision whether a sentence should be deleted.