Constituency Parsing

74 papers with code • 4 benchmarks • 6 datasets

Constituency parsing aims to extract a constituency-based parse tree from a sentence that represents its syntactic structure according to a phrase structure grammar.

Example:

             Sentence (S)
                 |
   +-------------+------------+
   |                          |
 Noun (N)                Verb Phrase (VP)
   |                          |
 John                 +-------+--------+
                      |                |
                    Verb (V)         Noun (N)
                      |                |
                    sees              Bill

Recent approaches convert the parse tree into a sequence following a depth-first traversal in order to be able to apply sequence-to-sequence models to it. The linearized version of the above parse tree looks as follows: (S (N) (VP V N)).

Most implemented papers

Grammar Induction with Neural Language Models: An Unusual Replication

nyu-mll/PRPN-Analysis EMNLP (ACL) 2018

A substantial thread of recent work on latent tree learning has attempted to develop neural network models with parse-valued latent variables and train them on non-parsing tasks, in the hope of having them discover interpretable tree structure.

Direct Output Connection for a High-Rank Language Model

nttcslab-nlp/doc_lm EMNLP 2018

This paper proposes a state-of-the-art recurrent neural network (RNN) language model that combines probability distributions computed not only from a final RNN layer but also from middle layers.

Unlexicalized Transition-based Discontinuous Constituency Parsing

mcoavoux/mtg_TACL TACL 2019

Lexicalized parsing models are based on the assumptions that (i) constituents are organized around a lexical head (ii) bilexical statistics are crucial to solve ambiguities.

Unsupervised Latent Tree Induction with Deep Inside-Outside Recursive Auto-Encoders

iesl/diora NAACL 2019

We introduce the deep inside-outside recursive autoencoder (DIORA), a fully-unsupervised method for discovering syntax that simultaneously learns representations for constituents within the induced tree.

PTB Graph Parsing with Tree Approximation

yosihide/ptb2cf ACL 2019

The Penn Treebank (PTB) represents syntactic structures as graphs due to nonlocal dependencies.

Sequence Labeling Parsing by Learning Across Representations

mstrise/seq2label-crossrep ACL 2019

We use parsing as sequence labeling as a common framework to learn across constituency and dependency syntactic abstractions.

Head-Driven Phrase Structure Grammar Parsing on Penn Treebank

DoodleJZ/HPSG-Neural-Parser ACL 2019

In details, we report 96. 33 F1 of constituent parsing and 97. 20\% UAS of dependency parsing on PTB.

Cross-Domain Generalization of Neural Constituency Parsers

dpfried/rnng-bert ACL 2019

Neural parsers obtain state-of-the-art results on benchmark treebanks for constituency parsing -- but to what degree do they generalize to other domains?