edu.stanford.nlp.trees
Class CollinsSemanticHeadFinder

java.lang.Object
  |
  +--edu.stanford.nlp.trees.CollinsSemanticHeadFinder

All Implemented Interfaces:

HeadFinder

public class CollinsSemanticHeadFinder

extends Object

implements HeadFinder

Implements the HeadFinder found in Michael Collins' 1999 thesis. Except: we've added a head rule for NX (returns rightmost), whereas no rule for the head of NX is found in any of the versions of Collins' head table that we have (did he perhaps use the NP rules for NX? Now this version chooses the semantic head verb rather than the verb form for cases with verbs. Should remember auxiliaries to differentiate past and passive, though.

Constructor Summary

CollinsSemanticHeadFinder()

Method Summary

Tree	determineHead(Tree t) Determine which daughter of the current parse tree is the head.
boolean	isVerbalAuxiliary(Tree t)
static void	main(String[] args) Go through trees and determine their heads and print them.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CollinsSemanticHeadFinder

public CollinsSemanticHeadFinder()

Method Detail

determineHead

public Tree determineHead(Tree t)

Determine which daughter of the current parse tree is the head. It assumes that the daughters alread have had their heads determined. It assumes that labels are a CategoryWordTag

Specified by:

determineHead in interface HeadFinder

Parameters:

t - The parse tree to examine the daughters of

Returns:

The parse tree that is the head

isVerbalAuxiliary

public boolean isVerbalAuxiliary(Tree t)

main

public static void main(String[] args)

Go through trees and determine their heads and print them. Just for debuggin' Use: java CollinsHeadFinder /wsj/07