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DESCRIPTION
Lexical models to improve parse selection
Citation preview
GR-Based Improved Parse Selection
Sriwantha Sri Aravinda Attanayake
University of Cambridge
Grammar Relations (GR)
John saw a cat with a telescope
Subject
Indirect Object
Determiner
Grammar Relations (GR)
<GR List>(ncsubj saw John )(iobj saw with )(dobj saw cat )(dobj with telescope )(det telescope a )(det cat a )
John saw a cat with a telescope
Luckily…
Parser
<GR List>(ncsubj saw John )(iobj saw with )(dobj saw cat )(dobj with telescope )(det telescope a )(det cat a )
Re RankingChoice 1(|ncsubj| |saw| |John| _)(|iobj| |saw| |with|)(|dobj| |saw| |cat|)(|dobj| |with| |telescope|)(|det| |telescope| |a|)(|det| |cat| |a|)
Choice 2(|ncsubj| |saw| |John| _)(|dobj| |saw| |cat|)(|det| |cat| |a|)(|ncmod| _ |cat| |with|)(|dobj| |with| |telescope|)(|det| |telescope| )
Choice 3(|ncsubj| |saw| |John| _)(|ncmod| _ |saw| |with|)(|dobj| |with| |telescope|)(|det| |telescope| |a|)(|dobj| |saw| |cat|)
John saw a cat with a telescope
a cat a + catNP DT+ NN
John saw a cat with a telescope
Saw + with : 80% cat + with : 40%
100 million wordBritish National Corpus
(BNC)
Parse1(|ncsubj| |saw| |John| _)(|iobj| |saw| |with|)(|dobj| |saw| |cat|)(|dobj| |with| |telescope|)(|det| |telescope| |a|)(|det| |cat| |a|)
Parse 2(|ncsubj| |saw| |John| _)(|dobj| |saw| |cat|)(|det| |cat| |a|)(|ncmod| |cat| |with|)(|dobj| |with| |telescope|)(|det| |telescope| |a| )
Parse 3(|ncsubj| |saw| |John| _)(|ncmod| _ |saw| |with|)(|dobj| |with| |telescope|)(|det| |telescope| |a|)(|dobj| |saw| |cat|)
Count=1000
Count=5000
2000
F-Score
(ncsubj saw John )(iobj saw with )(dobj saw cat )
(ncsubj saw John )
(ncsubj saw John )(iobj saw with )(dobj saw cat )(dobj with telescope)(det telescope a )(det cat a )
100% accurate, Poor recall
100% recall, Poor accuracy
Current Progress
F Score Improvement 1%MRR (10 Parses) about 6%
Challenges
(dobj saw cat ) Count=0(dobj saw dog) Count=0(dobj saw it) Count=3
(dobj saw {any word}) Count=45(dobj of and) Count=170,203
Score= Average (Count)
EndProduction of [email protected]