The Return of Lexical Dependencies: Neural Lexicalized PCFGs

07/29/2020
by   Yonatan Bisk, et al.
0

In this paper we demonstrate that context free grammar (CFG) based methods for grammar induction benefit from modeling lexical dependencies. This contrasts to the most popular current methods for grammar induction, which focus on discovering either constituents or dependencies. Previous approaches to marry these two disparate syntactic formalisms (e.g. lexicalized PCFGs) have been plagued by sparsity, making them unsuitable for unsupervised grammar induction. However, in this work, we present novel neural models of lexicalized PCFGs which allow us to overcome sparsity problems and effectively induce both constituents and dependencies within a single model. Experiments demonstrate that this unified framework results in stronger results on both representations than achieved when modeling either formalism alone. Code is available at https://github.com/neulab/neural-lpcfg.

READ FULL TEXT
research
06/24/2019

Compound Probabilistic Context-Free Grammars for Grammar Induction

We study a formalization of the grammar induction problem that models se...
research
03/23/2022

Geometry-Aware Supertagging with Heterogeneous Dynamic Convolutions

The syntactic categories of categorial grammar formalisms are structured...
research
05/31/2021

Neural Bi-Lexicalized PCFG Induction

Neural lexicalized PCFGs (L-PCFGs) have been shown effective in grammar ...
research
04/28/2021

PCFGs Can Do Better: Inducing Probabilistic Context-Free Grammars with Many Symbols

Probabilistic context-free grammars (PCFGs) with neural parameterization...
research
08/16/2023

Benchmarking Neural Network Generalization for Grammar Induction

How well do neural networks generalize? Even for grammar induction tasks...
research
10/15/2020

Montague Grammar Induction

We propose a computational modeling framework for inducing combinatory c...
research
02/23/2018

Unsupervised Grammar Induction with Depth-bounded PCFG

There has been recent interest in applying cognitively or empirically mo...

Please sign up or login with your details

Forgot password? Click here to reset