Chapter 25
Discourse Coherence
Chapter: Discourse Coherence, in Daniel Jurafsky and James H. Martin, Speech and Language Processing, 3rd edition draft, August 19, 2026.
Topics to learn
Page numbers refer to the linked chapter PDF.
- Relations p. 3
- Coherence relations p. 3
- Rhetorical Structure Theory p. 3
- The Penn Discourse TreeBank p. 5
- Parsing discourse structure p. 6
- Segmenting elementary discourse units p. 7
- RST parsing p. 7
- PDTB discourse parsing p. 9
- Entity-based local coherence p. 10
- Centering p. 10
- The entity grid p. 12
- Comparing neural and entity-based models p. 14
- Global structure p. 16
- Argumentation structure p. 17
- The structure of scientific discourse p. 18
FAQ
Is a discourse relation the same as a sentence connective?
No. A connective can mark a relation, but many relations have no explicit marker. Parsing has to recover the relation, not only the word.
What is an elementary discourse unit?
The span RST parsing treats as a leaf. Segmentation decides those spans before the tree is built. A wrong span makes the later relation comparison ambiguous.
What does an entity grid measure?
How entities appear, and in which grammatical roles, across neighboring sentences. It is a local coherence signal. It does not by itself recover a rhetorical tree.
Does local coherence imply a coherent document?
No. Neighboring sentences can be locally smooth while the document's global claim structure is broken. The chapter treats global coherence separately.