This document discusses dependency parsing and defines several key grammatical terms used in dependency parsing like root, advmod, aux, nsubj, dobj, and prep_for and prep_on. It also provides references for the Stanford Dependency Parser, IBM's English Slot Grammar Parser, and an introductory video about dependency parsing by Christopher Manning.
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Dependency parsing (2013)
1. Craig Trim / craigtrim@gmail.com / CCA 3.0
PART 2
Dependency
Parsing
3. Craig Trim / craigtrim@gmail.com / CCA 3.0root Sentence Root
The grammatical root of the sentence
4. Craig Trim / craigtrim@gmail.com / CCA 3.0advmod Adverbial Modifier.
Either an adverb or adverbial phrase that serves to modify the meaning of the word.
5. Craig Trim / craigtrim@gmail.com / CCA 3.0aux Auxiliary.
The non-main verb of the clause.
6. Craig Trim / craigtrim@gmail.com / CCA 3.0nsubj Nominal Subject.
A noun phrase which is the syntactic subject of a clause.
7. Craig Trim / craigtrim@gmail.com / CCA 3.0dobj Direct Object
The direct object of a Verb Phrase (VP).
8. Craig Trim / craigtrim@gmail.com / CCA 3.0prep_for Preposition (Collapsed Representation)
Any prepositional phrase that serves to modify the meaning of another verb, noun
9. Craig Trim / craigtrim@gmail.com / CCA 3.0prep_on Preposition (Collapsed Representation)
Any prepositional phrase that serves to modify the meaning of another verb, noun
The first step in dependency parsing is to look for the head of the sentence (the governor). We start with an artificial node (called Root), although this can be withheld from most diagrams. Phrase Structure (Deep Parsing) vs Dependency Structure (Dependency Parsing) A dependency grammar has the notion of a head. Officially, CGSs do not. A dependency parse can be extracted from a deep parse (using phrasal head rules) e.g. the head of a Noun Phrase is a noun/number/adj/ The head of a Verb Phrase is a verb/modal/
Relationship Definition: root - The root grammatical relation points to the root of the sentence. A fake node ROOT is used as the governor. The ROOT node is indexed with 0, since the indexation of real words in the sentence starts at 1. The token disable has been taken to the governor of this sentence. Every other token will flow from the governor as a dependency or modifier.
An adverbial modifier of a word is a (non-clausal) adverb or adverbial phrase (ADVP) that serves to modify the meaning of the word.
An auxiliary of a clause is a non-main verb of the clause, e.g. modal auxiliary, be and have in a composed tense.
A nominal subject is a noun phrase which is the syntactic subject of a clause. The governor of this relation might not always be a verb: when the verb is a copular verb, the root of the clause is the complement of the copular verb, which can be an adjective or noun.
The direct object of a VP is the noun phrase which is the (accusative) object of the verb.
A prepositional modifier of a verb, adjective, or noun is any prepositional phrase that serves to modify the meaning of the verb, adjective, noun, or even another prepositon. In the collapsed representation, this is used only for prepositions with NP complements.
A prepositional modifier of a verb, adjective, or noun is any prepositional phrase that serves to modify the meaning of the verb, adjective, noun, or even another prepositon. In the collapsed representation, this is used only for prepositions with NP complements.