Annotation for Argument Mining

Hi @sooheon. From what @honnibal told me in two other posts:

It's actually possible to create a NER model to classify spans as entities, but since they lack patterns in both semantics and even writing (regarding embeddings and letter-casing of the words), the model would have a great problem identifying the boundaries of the spans, and even the actual classes.

I'm not quite sure how to follow his suggestion to handle the boundary identification as a dependency parsing problem.