Dependency Grammar
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Chapter 14: Dependency Parsing
Speech and Language Processing. Daniel Jurafsky & James H. Martin. Copyright © 2021. All rights reserved. Draft of September 21, 2021. CHAPTER 14 Dependency Parsing The focus of the two previous chapters has been on context-free grammars and constituent-based representations. Here we present another important family of dependency grammars grammar formalisms called dependency grammars. In dependency formalisms, phrasal constituents and phrase-structure rules do not play a direct role. Instead, the syntactic structure of a sentence is described solely in terms of directed binary grammatical relations between the words, as in the following dependency parse: root dobj det nmod (14.1) nsubj nmod case I prefer the morning flight through Denver Relations among the words are illustrated above the sentence with directed, labeled typed dependency arcs from heads to dependents. We call this a typed dependency structure because the labels are drawn from a fixed inventory of grammatical relations. A root node explicitly marks the root of the tree, the head of the entire structure. Figure 14.1 shows the same dependency analysis as a tree alongside its corre- sponding phrase-structure analysis of the kind given in Chapter 12. Note the ab- sence of nodes corresponding to phrasal constituents or lexical categories in the dependency parse; the internal structure of the dependency parse consists solely of directed relations between lexical items in the sentence. These head-dependent re- lationships directly encode important information that is often buried in the more complex phrase-structure parses. For example, the arguments to the verb prefer are directly linked to it in the dependency structure, while their connection to the main verb is more distant in the phrase-structure tree. -
Dependency Grammars and Parsers
Dependency Grammars and Parsers Deep Processing for NLP Ling571 January 30, 2017 Roadmap Dependency Grammars Definition Motivation: Limitations of Context-Free Grammars Dependency Parsing By conversion to CFG By Graph-based models By transition-based parsing Dependency Grammar CFGs: Phrase-structure grammars Focus on modeling constituent structure Dependency grammars: Syntactic structure described in terms of Words Syntactic/Semantic relations between words Dependency Parse A dependency parse is a tree, where Nodes correspond to words in utterance Edges between nodes represent dependency relations Relations may be labeled (or not) Dependency Relations Speech and Language Processing - 1/29/17 Jurafsky and Martin 5 Dependency Parse Example They hid the letter on the shelf Why Dependency Grammar? More natural representation for many tasks Clear encapsulation of predicate-argument structure Phrase structure may obscure, e.g. wh-movement Good match for question-answering, relation extraction Who did what to whom Build on parallelism of relations between question/relation specifications and answer sentences Why Dependency Grammar? Easier handling of flexible or free word order How does CFG handle variations in word order? Adds extra phrases structure rules for alternatives Minor issue in English, explosive in other langs What about dependency grammar? No difference: link represents relation Abstracts away from surface word order Why Dependency Grammar? Natural efficiencies: CFG: Must derive full trees of many -
Dependency Grammar and the Parsing of Chinese Sentences*
Dependency Grammar and the Parsing of Chinese Sentences* LAI Bong Yeung Tom Department of Chinese, Translation and Linguistics City University of Hong Kong Department of Computer Science and Technology Tsinghua University, Beijing E-mail: [email protected] HUANG Changning Department of Computer Science and Technology Tsinghua University, Beijing Abstract Dependency Grammar has been used by linguists as the basis of the syntactic components of their grammar formalisms. It has also been used in natural langauge parsing. In China, attempts have been made to use this grammar formalism to parse Chinese sentences using corpus-based techniques. This paper reviews the properties of Dependency Grammar as embodied in four axioms for the well-formedness conditions for dependency structures. It is shown that allowing multiple governors as done by some followers of this formalism is unnecessary. The practice of augmenting Dependency Grammar with functional labels is discussed in the light of building functional structures when the sentence is parsed. This will also facilitate semantic interpretion. 1 Introduction Dependency Grammar (DG) is a grammatical theory proposed by the French linguist Tesniere.[1] Its formal properties were then studied by Gaifman [2] and his results were brought to the attention of the linguistic community by Hayes.[3] Robinson [4] considered the possiblity of using this grammar within a transformation-generative framework and formulated four axioms for the well-formedness of dependency structures. Hudson [5] adopted Dependency Grammar as the basis of the syntactic component of his Word Grammar, though he allowed dependency relations outlawed by Robinson's axioms. Dependency Grammar is concerned directly with individual words. -
Common and Distinct Neural Substrates for Pragmatic, Semantic, and Syntactic Processing of Spoken Sentences: an Fmri Study
Common and Distinct Neural Substrates for Pragmatic, Semantic, and Syntactic Processing of Spoken Sentences: An fMRI Study G.R.Kuperberg and P.K.McGuire Downloaded from http://mitprc.silverchair.com/jocn/article-pdf/12/2/321/1758711/089892900562138.pdf by guest on 18 May 2021 Institute of Psychiatry, London E.T.Bullmore Institute of Psychiatry, London and the University of Cambridge M.J.Brammer, S.Rabe-Hesketh, I.C.Wright, D.J.Lythgoe, S.C.R.Williams, and A.S.David Institute of Psychiatry, London Abstract & Extracting meaning from speech requires the use of difference between conditions in activation of the left-super- pragmatic, semantic, and syntactic information. A central ior-temporal gyrus for the pragmatic experiment than the question is:Does the processing of these different types of semantic/syntactic experiments; (2) a greater difference be- linguistic information have common or distinct neuroanatomi- tween conditions in activation of the right-superior and middle- cal substrates? We addressed this issue using functional temporal gyrus in the semantic experiment than in the syntactic magnetic resonance imaging (fMRI) to measure neural activity experiment; and (3) no regions activated to a greater degree in when subjects listened to spoken normal sentences contrasted the syntactic experiment than in the semantic experiment. with sentences that had either (A) pragmatical, (B) semantic These data show that, while left- and right-superior-temporal (selection restriction), or (C) syntactic (subcategorical) viola- regions may be differentially involved in processing pragmatic tions sentences. All three contrasts revealed robust activation of and lexico-semantic information within sentences, the left- the left-inferior-temporal/fusiform gyrus. -
Modeling Subcategorization Through Co-Occurrence Outline
Introducing LexIt Building Distributional Profiles Ongoing Work Conclusions Outline Modeling Subcategorization Through Co-occurrence 1 Introducing LexIt A Computational Lexical Resource for Italian Verbs The Project Distributional Profiles 1 2 Gabriella Lapesa ,AlessandroLenci 2 Building Distributional Profiles Pre-processing 1University of Osnabr¨uck, Institute of Cognitive Science Subcategorization Frames 2 University of Pisa, Department of Linguistics Lexical sets Selectional preferences Explorations in Syntactic Government and Subcategorisation nd University of Cambridge, 2 September 2011 3 Ongoing Work 4 Conclusions Gabriella Lapesa, Alessandro Lenci Modeling Subcategorization Through Co-occurrence 2/ 38 Introducing LexIt Introducing LexIt Building Distributional Profiles The Project Building Distributional Profiles The Project Ongoing Work Distributional Profiles Ongoing Work Distributional Profiles Conclusions Conclusions Computational approaches to argument structure LexIt: a computational lexical resource for Italian The automatic acquisition of lexical information from corpora is a longstanding research avenue in computational linguistics LexIt is a computational framework for the automatic acquisition subcategorization frames (Korhonen 2002, Schulte im Walde and exploration of corpus-based distributional profiles of Italian 2009, etc.) verbs, nouns and adjectives selectional preferences (Resnik 1993, Light & Greiff 2002, Erk et al. 2010, etc.) LexIt is publicly available through a web interface: verb classes (Merlo & Stevenson 2001, Schulte im Walde 2006, http://sesia.humnet.unipi.it/lexit/ Kipper-Schuler et al. 2008, etc.) Corpus-based information has been used to build lexical LexIt is the first large-scale resource of such type for Italian, resources aiming at characterizing the valence properties of predicates cf. VALEX for English (Korohnen et al. 2006), LexSchem for fully on distributional ground French (Messiant et al. -
Dependency Grammar
Dependency Grammar Introduc)on Christopher Manning Dependency Grammar and Dependency Structure Dependency syntax postulates that syntac)c structure consists of relaons between lexical items, normally binary asymmetric relaons (“arrows”) called dependencies submitted Bills were by on Brownback ports Senator Republican and immigration of Kansas Christopher Manning Dependency Grammar and Dependency Structure Dependency syntax postulates that syntac)c structure consists of relaons between lexical items, normally binary asymmetric relaons (“arrows”) called dependencies submitted nsubjpass auxpass prep The arrows are Bills were by commonly typed prep pobj with the name of on Brownback pobj nn appos grammacal ports Senator Republican relaons (subject, cc conj prep preposi)onal object, and immigration of apposi)on, etc.) pobj Kansas Christopher Manning Dependency Grammar and Dependency Structure Dependency syntax postulates that syntac)c structure consists of relaons between lexical items, normally binary asymmetric relaons (“arrows”) called dependencies submitted The arrow connects a nsubjpass auxpass prep head (governor, Bills were by superior, regent) with a prep pobj dependent (modifier, on inferior, subordinate) Brownback pobj nn appos ports Senator Republican Usually, dependencies cc conj prep form a tree (connected, and immigration of acyclic, single-head) pobj Kansas Christopher Manning Dependency Grammar and Dependency Structure ROOT Discussion of the outstanding issues was completed . • Some people draw the arrows one way; some the other way! • Tesnière had them point from head to dependent… • Usually add a fake ROOT so every word is a dependent of precisely 1 other node Christopher Manning Dependency Grammar/Parsing History • The idea of dependency structure goes back a long way • To Pāṇini’s grammar (c. -
Dependency Grammar Induction Via Bitext Projection Constraints
Dependency Grammar Induction via Bitext Projection Constraints Kuzman Ganchev and Jennifer Gillenwater and Ben Taskar Department of Computer and Information Science University of Pennsylvania, Philadelphia PA, USA {kuzman,jengi,taskar}@seas.upenn.edu Abstract ing recent interest in transferring linguistic re- sources from one language to another via parallel Broad-coverage annotated treebanks nec- text. For example, several early works (Yarowsky essary to train parsers do not exist for and Ngai, 2001; Yarowsky et al., 2001; Merlo many resource-poor languages. The wide et al., 2002) demonstrate transfer of shallow pro- availability of parallel text and accurate cessing tools such as part-of-speech taggers and parsers in English has opened up the pos- noun-phrase chunkers by using word-level align- sibility of grammar induction through par- ment models (Brown et al., 1994; Och and Ney, tial transfer across bitext. We consider 2000). generative and discriminative models for Alshawi et al. (2000) and Hwa et al. (2005) dependency grammar induction that use explore transfer of deeper syntactic structure: word-level alignments and a source lan- dependency grammars. Dependency and con- guage parser (English) to constrain the stituency grammar formalisms have long coex- space of possible target trees. Unlike isted and competed in linguistics, especially be- previous approaches, our framework does yond English (Mel’cuk,ˇ 1988). Recently, depen- not require full projected parses, allowing dency parsing has gained popularity as a simpler, partial, approximate transfer through lin- computationally more efficient alternative to con- ear expectation constraints on the space stituency parsing and has spurred several super- of distributions over trees. -
Three Dependency-And-Boundary Models for Grammar Induction
Three Dependency-and-Boundary Models for Grammar Induction Valentin I. Spitkovsky Hiyan Alshawi Stanford University and Google Inc. Google Inc., Mountain View, CA, 94043 [email protected] [email protected] Daniel Jurafsky Stanford University, Stanford, CA, 94305 [email protected] Abstract DT NN VBZ IN DT NN [The check] is in [the mail]. We present a new family of models for unsu- | {z } | {z } pervised parsing, Dependency and Boundary Subject Object models, that use cues at constituent bound- Figure 1: A partial analysis of our running example. aries to inform head-outward dependency tree generation. We build on three intuitions that Consider the example in Figure 1. Because the are explicit in phrase-structure grammars but determiner (DT) appears at the left edge of the sen- only implicit in standard dependency formu- tence, it should be possible to learn that determiners lations: (i) Distributions of words that oc- may generally be present at left edges of phrases. cur at sentence boundaries — such as English This information could then be used to correctly determiners — resemble constituent edges. parse the sentence-internal determiner in the mail. (ii) Punctuation at sentence boundaries fur- ther helps distinguish full sentences from Similarly, the fact that the noun head (NN) of the ob- fragments like headlines and titles, allow- ject the mail appears at the right edge of the sentence ing us to model grammatical differences be- could help identify the noun check as the right edge tween complete and incomplete sentences. of the subject NP. As with jigsaw puzzles, working (iii) Sentence-internal punctuation boundaries inwards from boundaries helps determine sentence- help with longer-distance dependencies, since internal structures of both noun phrases, neither of punctuation correlates with constituent edges. -
Towards an Implelnentable Dependency Grammar
Towards an implementable dependency grammar Timo JKrvinen and Pasi Tapanainen Research Unit for Multilingual Language Technology P.O. Box 4, FIN-00014 University of Helsinki, Finland Abstract such as a context-free phrase structure gram- mar. This leads us to a situation where the Syntactic models should be descriptively ade- parsing problem is extremely hard in the gen- I quate and parsable. A syntactic description is eral, theoretical case, but fortunately parsable autonomous in the sense that it has certain ex- in practise. Our result shows that, while in gen- plicit formal properties. Such a description re- eral we have an NP-hard parsing problem, there i lates to the semantic interpretation of the sen- is a specific solution for the given grammar that tences, and to the surface text. As the formal- can be run quickly. Currently, the speed of the ism is implemented in a broad-coverage syntac- parsing system I is several hundred words per tic parser, we concentrate on issues that must I second. be resolved by any practical system that uses In short, the grammar should be empirically such models. The correspondence between the motivated. We have all the reason to believe structure and linear order is discussed. ! that if a linguistic analysis rests on a solid de- scriptive basis, analysis tools based on the the- 1 Introduction ory would be more useful for practical purposes. i The aim of this paper is to define a dependency We are studying the possibilities of using com- grammar framework which is both linguistically putational implementation as a developing and motivated and computationally parsable. -
Acquiring Verb Subcategorization from Spanish Corpora
Acquiring Verb Subcategorization from Spanish Corpora Grzegorz ChrupaÃla [email protected] Universitat de Barcelona Department of General Linguistics PhD Program “Cognitive Science and Language” Supervised by Dr. Irene Castell´onMasalles September 2003 Contents 1 Introduction 5 2 Verb Subcategorization in Linguistic Theory 7 2.1 Introduction . 7 2.2 Government-Binding and related approaches . 7 2.3 Categorial Grammar . 9 2.4 Lexical-Functional Grammar . 11 2.5 Generalized Phrase-Structure Grammar . 12 2.6 Head-Driven Phrase-Structure Grammar . 14 2.7 Discussion . 17 3 Diathesis Alternations 19 3.1 Introduction . 19 3.2 Diathesis . 19 3.2.1 Alternations . 20 3.3 Diathesis alternations in Spanish . 21 3.3.1 Change of focus . 22 3.3.2 Underspecification . 26 3.3.3 Resultative construction . 27 3.3.4 Middle construction . 27 3.3.5 Conclusions . 29 4 Verb classification 30 4.1 Introduction . 30 4.2 Semantic decomposition . 30 4.3 Levin classes . 32 4.3.1 Beth Levin’s classification . 32 4.3.2 Intersective Levin Classes . 33 4.4 Spanish: verbs of change and verbs of path . 35 4.4.1 Verbs of change . 35 4.4.2 Verbs of path . 37 4.4.3 Discussion . 39 4.5 Lexicographical databases . 40 1 4.5.1 WordNet . 40 4.5.2 VerbNet . 41 4.5.3 FrameNet . 42 5 Subcategorization Acquisition 44 5.1 Evaluation measures . 45 5.1.1 Precision, recall and the F-measure . 45 5.1.2 Types and tokens . 46 5.2 SF acquisition systems . 47 5.2.1 Raw text . -
Features from Aspects Via the Minimalist Program to Combinatory Categorial Grammar
Á. Gallego & D. Ott (eds.). 2015. 50 Years Later: Reflections on Chomsky’s Aspects. Cambridge, MA: MITWPL. Available for purchase at http://mitwpl.mit.edu © The Authors FEATURES FROM ASPECTS VIA THE MINIMALIST PROGRAM TO COMBINATORY CATEGORIAL GRAMMAR NEIL SMITH ANNABEL CORMACK University College London 1 Background One major contribution of Aspects (Chomsky 1965)1 was to initiate the development of a theory of syntactic features. There is no use of features, either syntactic or morphophonemic, in Chomsky’s earliest work The Morphophonemics of Modern Hebrew (1951/79); they do not appear in his monumental The Logical Structure of Linguistic Theory (1955/75); nor in Syntactic Structures (1957) (except for category labels); nor, except for phonological distinctive features, in Current Issues in Linguistic Theory (1964). In Aspects features play a crucial role. Chomsky suggests (p.214) that “We might, then, take a lexical entry to be simply a set of features, some syntactic, some phonological, some semantic”. But even here the use of features was somewhat haphazard, apparently unconstrained, and a terminological mess. In this contribution we want to trace – in broad outline – the development of a theory of morphosyntactic features and propose a fully Merge-based and parsimonious version of such a theory. Our work is intended as a contribution to Chomsky’s Minimalist Program, pursuing the same ends on the basis of some different background assumptions. These assumptions and the specific analyses derived from them have been developed using an austere version of Combinatorial Categorial Grammar, but are of wider applicability. All current theories use phonological features and ‘semantic’ features which we will largely ignore except to point out that the term ‘semantic’ is used in radically different ways to cover truth-theoretic, conceptual or encyclopaedic distinctions. -
Dependency Parsing
Dependency Parsing Sandra Kubler¨ LSA Summer Institute 2017 Dependency Parsing 1(16) Dependency Syntax ◮ The basic idea: ◮ Syntactic structure consists of lexical items, linked by binary asymmetric relations called dependencies. ◮ In the words of Lucien Tesni`ere: ◮ La phrase est un ensemble organis´e dont les ´el´ements constituants sont les mots. [1.2] Tout mot qui fait partie d’une phrase cesse par lui-mˆeme d’ˆetre isol´ecomme dans le dictionnaire. Entre lui et ses voisins, l’esprit aper¸coit des connexions, dont l’ensemble forme la charpente de la phrase. [1.3] Les connexions structurales ´etablissent entre les mots des rapports de d´ependance. Chaque connexion unit en principe un terme sup´erieur `aun terme inf´erieur. [2.1] Le terme sup´erieur re¸coit le nom de r´egissant. Le terme inf´erieur re¸coit le nom de subordonn´e. Ainsi dans la phrase Alfred parle [. ], parle est le r´egissant et Alfred le subordonn´e. [2.2] Dependency Parsing 2(16) Dependency Syntax ◮ The basic idea: ◮ Syntactic structure consists of lexical items, linked by binary asymmetric relations called dependencies. ◮ In the words of Lucien Tesni`ere: ◮ The sentence is an organized whole, the constituent elements of which are words. [1.2] Every word that belongs to a sentence ceases by itself to be isolated as in the dictionary. Between the word and its neighbors, the mind perceives connections, the totality of which forms the structure of the sentence. [1.3] The structural connections establish dependency relations between the words. Each connection in principle unites a superior term and an inferior term.