address syntactic ambiguity rising from sentence structures - e.g. attachment of prepositional phrases
used for POS Tagging
prepositional phrases always begin with a preposition
examples
- I saw the man on the hill with a telescope (with can be attached to me or man)
- The violent police man injures the farmer with an ax (with can be attached to farmer or injures)
- John swerved and hit a tree riding his bike (riding can be attached to tree or hit)
- Killer sentenced to die for second time in 10 years (for can be attached to die or sentenced)
- Flying planes can be dangerous (can may be attached to planes or flying)
attachment/connection/dependencies → modifying/specifying/describing another word which forms the sentence structure
Approaches
- dependency structure based
- phrase structure based
Depending on the interpretations of where the prepositional phrase is supposed to connect, we get different graphs for both approaches.