Dependency Grammar & Stanford Dependencies Wentao Ding

History linguistic units (e.g. words), are connected to each other by directed links The (finite) verb is taken to be the structural center of clause structure. 

Dependency vs Constituency

Grammar Relations In linguistics, grammatical refer to functional relationships between constituents in a clause. Thematic criteria Configurational criteria Morphological criteria Prototypical traits

Universal Dependencies Used in Stanford CoreNLP http://universaldependencies.org/ The annotation scheme is based on an evolution of (universal) Stanford dependencies (de Marneffe et al., 2006, 2008, 2014) Google universal part-of-speech tags (Petrov et al., 2012) The Interset interlingua for morphosyntactic tagsets (Zeman, 2008).

Syntax Relations in UD Nominals Clauses Modifier words Function Words Core arguments nsubj csubj obj ccomp iobj xcomp Non-core dependents obl advcl advmod* aux vocative discourse cop expl mark dislocated Nominal dependents nmod acl amod det appos clf nummod case Coordination MWE Loose Special Other conj fixed list orphan punct cc flat parataxis goeswith root compound reparandum dep

Syntax Relations in UD Basic Dependencies Simple Clauses Nominals Complex clauses Others Coordination Ellipsis Multiword Expressions Comparatives Paratactic Constructions Punctuation

Clauses Relations in UD Basic Dependencies-Complex Clause Relation Coordinated clauses conj Subordinate clauses Clausal subjects—csubj Clausal complements—xcomp/ccomp Adverbial clause—advcl Adnominal clause—acl Secondary Predicates She declared the cake beautiful. xcomp

Stanford Dependency Parser A  transition-based parser powered by a neural network which accepts word embedding inputs http://stp.lingfil.uu.se/~nivre/docs/eacl3.pdf

Stanford Dependency Parser compute the hidden layer ℎ 𝑐 ∈ ℝ 𝑑 ℎ , and pick the transition with the highest score pre-compute matrix operations for most top frequent 10, 000 words and all positions and all POS tags and arc labels

Stanford Dependency Parser Label Attachment Score (LAS) % of tokens with correct HEAD and DEPREL Unlabeled Attachment Score (UAS) % of tokens with correct HEAD Development (1700 sentences) Test (2416 sentences)

References https://en.wikipedia.org/wiki/Dependency_grammar https://en.wikipedia.org/wiki/Grammatical_relation http://universaldependencies.org/u/dep/all.html De Marneffe, Marie-Catherine, and Christopher D. Manning. Stanford typed dependencies manual. Technical report, Stanford University, 2008. De Marneffe, Marie-Catherine, et al. "Universal Stanford dependencies: A cross-linguistic typology." LREC. Vol. 14. 2014. Chen, Danqi, and Christopher D. Manning. "A Fast and Accurate Dependency Parser using Neural Networks." EMNLP. 2014.

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