Attachment Ambiguity I
When we try to determine the syntactic structure of a sentence, there are often phrases that can be attached to two or more different nodes in the tree. Which one is correct?
A simple model for this problem consists of computing the following likelihood ratio: ?(v, n, p) = log (P(p|v)/P(p|n)) where P(p|v) is the probability of seeing a PP with p after the verb v and P(p|n) is the probability of seeing a PP with p after the noun n.
Weakness of this model: it ignores the fact that other things being equal, there is a preference for attaching phrases “low” in the parse tree.