LING 6520: Comparative Topics in Linguistics (from a computational perspective)Martha Palmer

Jan 15, 2008

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What does Linguistics offer Computational Lexical Semantics?

What does Computational Lexical Semantics offer Linguistics?

What can we do together?

Linguistics → CLS

• Syntactic structure – dependencies• Jackendoff

– Lexical Conceptual Structures• Fillmore, Talmy, Dowty, ….

– Case frames, conceptual analyses, proto-roles,….• Levin’s English verb classes

– Other languages?• Lexicographic sense distinctions• Discourse structure• Event representations

CLS → Linguistics

• Quantitative analysis of data– Frequency counts, mutual information, automatic

clustering, new & varied classifications– Word co-occurrences, subcat frame distributions, pp

attachment preferences, word alignments– tomorrow

• Grammatical formalisms – TAG’s, LFG’s, CCG’s, HPSG’s– Alternative building blocks for human sentence

processing – models of regular sense extensions

Feature-based Lexicalized Tree-Adjoining Grammars

Joshi,et al 75, Joshi 85,

• Elementary trees – Initial trees– Auxiliary trees

• Two operations– Substitution– Adjunction

Same event - different syntactic frames

John broke windows. SUBJ VERB OBJ

Windows broke. SUBJ VERB

Syntactic Parses

Elementary Trees

SubstitutionS

V

NP↓

NP↓

VP

break

NP

John

NP

the

Ndet

window

SubstitutionS

V

NP↓

NP↓

VP

break

NP

John

NP↓

the

Ndet

window

Derived TreeS

V

NP↓

NP ↓

VP

John

the

N

break

det

window

Feature-based SubstitutionS

V

NP↓

NP↓

VP+sing +past

break

NP+sing

John

NP

the

Ndet

window

4/1/04

Derived Tree w/ FeaturesS

V

NP+sing

NP↓

VP +sing +past

John

the

N

break

det

window

4/1/04

AdjunctionS

V

NP↓

NP↓

VP

John

the

N

break

det

window

VP

quickly

VP *Adv

4/1/04

Adjunction (cont.)S

NP↓

JohnV

VP *

break

NP↓

the

Ndet

window

VP

quickly

Adv

4/1/04

Extending Senses Through Adjunction