LING 6520: Comparative Topics in Linguistics (from a computational perspective) Martha Palmer Jan 15,

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

Substitution S V NP↓ VP break NP John NP the N det window

Substitution S V NP↓ VP break NP John NP ↓ the N det window

Derived Tree S V NP↓ VP John the N break det window

Feature-based Substitution S V NP↓ VP+sing +past break NP+sing John NP the N det window

4/1/04 Derived Tree w/ Features S V NP+sing NP ↓ VP +sing +past John the N break det window

4/1/04 Adjunction S V NP↓ VP John the N break det window VP quickly VP * Adv

4/1/04 Adjunction (cont.) S NP↓ John V VP * break NP ↓ the N det window VP quickly Adv

4/1/04 Extending Senses Through Adjunction