span?

[John Bateman]

> Could someone explain to me exactly how a 'span' is determined? Is it
> a grammatical unit? A pragmatic unit?

It is an *analytic* unit defined internally to RST. That is, you decide
on your
criteria for segmentation (as in all linguistic endeavors), and then use
this
for your spans. Then you see if you can make an RST analysis work.

A common choice is to make spans co-incident with clauses (then it
*corresponds* to a grammatical unit, but it is not itself a grammatical
unit as it belongs to a different level of description).

In some work, it goes below clauses to phrases (e.g., in German where
what would be a subordinating clause in English happily appears as
a prepositional phrase and it seems a pity to have completely different
RST analyses).

It could be bigger units, such as paragraphs if you want less granularity.

I am not sure what a "pragmatic unit" is and so have no comments.

Best,
John Bateman.