Questions tagged [parsing]

The process of syntactic analysis, usually used in the context of computational linguistics.

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264 views

Average number of independent clauses in a compound sentence

I'm working on a NLP project, where we analyze large text samples (think a novel), and produce some metrics that help us answer interesting questions about the text. One of these metrics is average ...
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What are the most authoratative references on the notion of shallow parsing?

What are the most authoratative references on the notion of shallow parsing (also known as text chunking) in NLP? I am looking for definitions, examples, and discussion of strings of words that ...
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Inside-outside algorithm (PCFG learning) and binarization

I am implementing the Inside-outside algorithm to estimate the parameters of a PCFG based on the train corpus. One observation (on existing implementations) is that, the grammar is converted into ...
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138 views

Methods to dissect or parse long, difficult sentences

TL;DR: Only English and French can I manage and so ask for. Instead of repeating 'long, difficult' hereafter, denote it mazy. Mazy sentences still stifle my reading comprehension; so I was gladdened ...
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888 views

What it the best algorithm for dependency parsing?

There are quite a few statistical parsers but I'm interested in rule-based dependency parsing. I have a lexicon, i.e., a list of words with lemmas, POS, and morphological features. What is the best ...
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351 views

How do PCFG parsers actually work?

I'm new to NLP. I have a few doubts about PCFG parser (NLTK). My understanding is that PCFG parser will return most probable parse tree. So if I'm parsing one sentence with PCFG parser, I'll be ...
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1answer
1k views

Steps to build a dependency parser [closed]

I'm a beginner in NLP. What are the main steps to build a dependency parser? thanks.
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748 views

Earley Parser: Ambiguity

I've got a pretty basic question concerning the Earley parser: In case of syntactic ambiguity ( S -> NP VP(V NP(NP PP)) vs. S -> NP VP(VP((V NP) PP) ), are both parses stored in one chart or in two? ...
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1answer
101 views

How should grammatical errors be treated in parsing and tokenisation?

I'm writing a tokenizer/parser thing to parse & diagram a bunch of sentences gathered from ordinary language use. Most of it parses just fine by following rules, but from time to time there are ...
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1answer
528 views

What are the major sources of error for state-of-the-art parsers?

I'm especially interested in parsing sentences written in English (dependency or constituency). Ideally I'd like to have an estimation of how much improvement solving each of those major sources of ...
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349 views

Theory behind the semantics of predicates

My goal is to build semantic representation of Russian sentences, i.e. to extract verb predicates and fill in the actant words. The tool I have is some kind of a shallow syntactic parser which works ...
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488 views

Which dependency parsers take auxiliaries to to be heads over content verbs and prepositions to be heads over their complements?

The Universal Stanford Dependencies (USD) parsing scheme subordinates auxiliary verbs to content verbs and prepositions to their complements: http://nlp.stanford.edu/~manning/papers/...
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Parsing sentences

A layman's question: Given a sentence whose meaning is unique, is there any standard algorithm to uniquely determine/describe its grammatical structure such that it can be classified in a standard way ...
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1answer
568 views

Please help me parse the subject complement of

The 2 questions are on the diagram. In question 1 - I emphasize "function as" because my understanding is that (in English) a predicate nominative - even though it can take the form of a preposition ...
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2k views

Relative clauses in X-Bar

How do I break down the Complement further in accordance with X bar theory.
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1answer
508 views

What's the difference between discontinuity and discontinuous dependencies?

I am reading the Wikpedia page on discontinuities, it says: Worth noting is that a large majority of sentences in most languages are projective, i.e. they do not contain discontinuities. Only ...
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226 views

What is the maximum accuracy that can achieve a projective dependency parser in English?

From what I understand: a projective dependency parsers can only output projective tree Wikipedia says: "a large majority of sentences in most languages are projective, i.e. they do not contain ...
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Do constituency parsers always generate POS tags? [closed]

For example, Cer, Daniel M., et al. "Parsing to Stanford Dependencies: Trade-offs between Speed and Accuracy." LREC. 2010. : All 5 presented constituency parsers generate POS tags. Do constituency ...
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Why is dependency parsing so much faster than constituency parsing?

For example, Cer, Daniel M., et al. "Parsing to Stanford Dependencies: Trade-offs between Speed and Accuracy." LREC. 2010. : Why is dependency parsing so much faster than constituency parsing?
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638 views

In what situation a constituency-based tree cannot be constructed from a dependency-based tree?

I am confused regarding the distinction dependency- vs. constituency-based tree: to me they look like they encompass the same information but presented differently. E.g. in the Wikipedia example the ...
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7k views

How is the F1 score computed when assessing dependency parsing?

For example http://naacl2013.naacl.org/Documents/deep-learning-for-nlp-naacl-2013-tutorial.pdf says "+1.4% F1 Dependency Parsing". How is the F1 score computed when comparing dependency-based parse ...
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Node level with Stanford dependency parser

I am trying to find a way to select the node(word) level using Stanford dependency parser. But, i haven't found any method that help to get the node level. I will be very grateful for your help
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Is 'It' anaphoric or cataphoric, and what is its antecedent/postcedent?

Question 1a: What does 'It' refer to in the following sentence: It was clearly in the mood to place acknowledgements at the bottom of questions. The context for the above sentence is provided in ...
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209 views

Dependency Grammar constraints

I study dependency grammar, DG and I have a question regarding constraints of DG. I do understand why do we need constituency grammars, CG and DG, however I don't completely understand the ...
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2k views

Stanford parse tree - What does SBAR mean?

I am wondering what SBAR means and how do I correctly represent in a tree this sentence? Why there are 2 S? Original sentence is: After she ate the cake, Emma visited Tony in his room. Thank you! (...
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177 views

Are there grammars for subset of English?

I'm looking for grammar for relatively simple subset of English, tokens in which contain only letters, digits and comma. No quotes, colons, dashes and so on. Is there such thing? If no, is there other ...
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620 views

Parsing a simple sentence?

I am doing natural language processing and I am trying to figure out how to parse the following sentence (I am using BNC tags to mark parts of speech): Have I seen the man? As far as I see it is ...
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Is there a favoured data structure for storing ambiguous parse trees in Natural Language Processing?

I know a bit about parsing computer languages. Generally they try to resolve all ambiguities when parsing or abort the parse and throw an error. This means you either got nothing because there was an ...
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680 views

Algorithm for converting an English sentence or phrase into a function call [closed]

Let's say I have a command line app that has the following functions: function createABox() { console.log("hey"); }; function deleteABox() { console.log("wutsup"); }; The command line app can take ...
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Can parsing be classified to some complexity class (e.g. NP-complete)?

In computer science (especially computational complexity theory), problems can be classified to some complexity theory. For example, we say the travelling salesman problem belongs to NP-complete. ...
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1answer
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Is there a measure of how easy a sentence is to parse as a Natural Language problem?

Reading the news report for the AP Twitter hoax: Breaking: Two Explosions in the White House and Barack Obama is injured. I'm thinking this is the most unambiguous and perfect stock market bomb. ...
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690 views

Text parsing: Distinguish between “dictionary words” and names

I have texts in English and German containing "dictionary words" and names. e.g. "... In Florence the painter Leonardo built ..." I have a Java program where need to determine for each word if it ...
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1answer
226 views

What markers can one use to automatically detect a prepositional phrase in an English sentence?

I'm currently working on a project for which I have a need to identify certain aspects of a sentence. What markers can I use to algorithmically detect a prepositional phrase in a sentence? Obviously, ...
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514 views

Small English parser written in Java

I need an English parser written in Java with a small memory/processing input. I have used the Stanford parser, but it is rather heavy. I am also considering using the link grammar parser, which is ...
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1answer
223 views

How to parse text too variable for formal grammars but too constrained for NLP?

I'm dealing with a corpus of text that is written informally, but generally conforms to a very standard format by convention (think something like Froyo Frozen Yogurt, Smucker's Peanut Butter) and ...
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3k views

Is there a well-established metric to measure the effectiveness of a parsing algorithm?

My understanding that 100% accurate parsing (analyzing a text and creating a syntactic tree) is an impossible task for computational linguistics at this moment. However, there are many heuristics or ...
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5answers
3k views

Which language would be easiest for a computer to parse?

I have an idea for a programming language that would work more like a spoken language. "sentences" would have an initial context in which specific subjects, verbs, and objects would have meaningful ...
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422 views

Is there a standard corpus against which to benchmark mechanical parsers?

I was wondering if there is a published standard corpus of English sentences which are confounding for mechanical parsers. I am looking over sentences given here, and I have the following (very short) ...

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