MODELLING OF SHALLOW PARSING OF INDIAN LANGUAGES IIT MUMBAI April 2-4, 2006 Identification of Relative Clause as a Nominal Dependency Relation

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MODELLING OF SHALLOW PARSING OF INDIAN
LANGUAGESIIT MUMBAIApril 2-4,
2006Identification of Relative Clause as a
Nominal Dependency Relation

• Tanmoy Bhattacharya Nguyen Chi Duy Khuong
• tanmoy1_at_gmail.com khuongvn2000_at_yahoo.com
• Department of Linguistics
• University of Delhi

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The Problem

• Implementable formalisms (e.g. HPSG) have two
  problems with adjuncts
• Identifying the adjunct (RECOGNITION)
• Determining the place the adjunct belongs
  (ADDRESSING TECHNIQUE)
• Solution using a selectional RC theory within
  Principles Parameters framework

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The Solution in Brief

• Both the RECOGNITION and the ADDRESSING problems
  can be bypassed if there is no adjunct to start
  with
• 3
• The flower that John bought
• selectional relation

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The Problem in GeneralFunctor versus Argument

• The ARGUMENT view
• Head XP COMPLEMENT
• The FUNCTOR view
• Head XP ADJUNCT
• Head-Complement idea is conducive to HPSG as it
  is easier to see complements as semantic
  arguments of their heads

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The Argument View

• Can explain diagnostics
• (i) Semantic Constancy
• a. Sharma sleeps/ snores/ laughs in the seminar
• b. Sharma depends/ relies on a mouse
• (ii) Iterability
• Sharma opened the drawer with a key, with a
  hammer
• (iii) Order
• The police blamed the riot on the residents
  without checking the facts

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The Functor View

• Cannot be imported to HPSG easily
• SUBCAT cannot handle it since
• Different adjuncts attach to different heads
• Not a Head-Filler semantics
• Adjunct relation is syntactically different
  since
• Broader range of categories modified
• Number of adjuncts is not pre-fixed
• How do we handle it then?

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Classic HPSG The duality of representation

• Pollard and Sag (1987) adjunct-main clause
  dependency determined by rules of grammar
  specification neither on N or the RC
• Assumes Type hierarchy
• Rule of RC
• HEAD MAJ N
• HEAD-DTRSYNLOC NFORM NORM
• DTRS LEX __
• ADJ-DTRSYNRELCLAUSE

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HPSG Structure for an RC

• PHON solution that I like
• HEAD 1
• SYN LOC SUBCAT 2
• LEX _
• PHON solution
• MAJ N
• HEAD-DTR HEAD 1 NFORM NORM
• DTRS SYNLOC
• SUBCAT 2 ?DET?
• LEX _
• PHON that I like
• ADJ-DTR SYN RELCLAUSE

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Problems with the Classic HPSG

• A large number of such rules required
• The solution rests on hierarchy of types/
  subtypes (head-structure and head-adjunct-structur
  e respectively)
• Phrase
• qo
• CLAUSALITY HEADEDNESS
• qo qo
• Clause non-clause hd-ph non-hd-ph
• tu
• .. rel-cl hd-adj-ph

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Unification

• Desirable Unification within the rule
• BUT, who is selecting whom? (Functor/ Argument
  problem)
• Functor alternative is attractive but not
  formalizable
• So, modified heads selecting adjuncts (Kayne)
• Every common N bearing head feature ADJUNCT
• a head-adjunct rule
• HEAD-DTRSYNLOC HEADADJUNCT..1..
• DTRS LEX __
• ADJ-DTRSYN 1

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HPSG schemata for solution that I like

• PHON solution that I like
• HEAD 1
• SYN LOC SUBCAT 2
• LEX _
• PHON solution
• MAJ N
• HEAD-DTR HEAD 1 NFORM NORM
• ADJUNCTS lt..3..gt
• DTRS SYNLOC
• SUBCAT 2 ?DET?
• LEX _
• PHON that I like
• ADJ-DTR SYN 3 RELCLAUSE

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Revised HPSG

• Highest V rather than a null relativizer heads
  the clause
• S
• MOD N
• qo
• NP VP
• MOD N
• wi
• NP V
• MOD N
• John-I chayk-ul neh-un
• -nom book-acc put-rel
• The book that John put
• Sag (1997)

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Highest V in RC need not show RC morphology

• Watashi ga inu ga taberu ring-o miru
  
• I NOM dog NOM eats apple-ACC see
• I see the apple which the dog eats.
• IP
• 3
• watashi ga I
• 3
• VP I
• 3
• NP V
• 3 miru
• CP NP
• 6
• inuga taberu ringo
• Similarly with Vietnamese

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Sag (1997) Solution

• who (relative)
• CAT NP
• CONT INDEX 3
• REL 3
• QUE
• The head words have a REL feature
• Inheritance of REL is governed by WHIP

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Drawbacks of Revised HPSG

• Hierarchy of types as before
• Wh-relatives are wh-rel-cl and subject to a
  separate constraint
• Subject Wh-relatives belong to yet another type
  and subject to yet another constraint
• Non-subject relatives belong to another subtype
  and subject to another constraint
• And so on

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Semantics of the Gap

• Hunter (2004)
• I eat the apples which the men bought.

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Linking the two clauses
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Back to the Duality of Representation

• CP generated from the semantics of the RC is
  added as an adjunct to the NP.
• Doesnt address either the RECOGNITION or the
  ADDRESSING problem
• One feature for the RC (relativewh) and one for
  the MC (subclause0)
• Can we bypass this problem?