In §4 we established that our discriminativelytrained neural aligner outperforms unsupervised baselines, especially on NER spans; in §5 we verified that the alignments it produces can be productively applied a downstream IE task (NER) via dataset projection.
unlike these unsupervised baselines, our aligner requires labelled data on the order of thousands of sentences, and thus cannot be applied to language pairs for which no labelled alignment data exists (most languages).