Constituency Parsing

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

Description from the archive archive 2025-07-28.

Benchmarks archive 2025-07-28

4 leaderboard tables shown for this task, 4 with rows (a “benchmark” on this site is a table with at least one row, as on /sota), ordered by row count. “Best model” is the first row in the archive's own order at snapshot; nothing is re-ranked here and metric direction is not recorded in the archive. PwC's Trend sparklines are not in the archive, so that column is omitted.

Syntology column: samples harvested from the paper's repositories and executed on synthesized fixtures; “ran” is not a correctness claim and does not order the table. A dash means no Syntology record for that paper, not a recorded non-run. Read from the graph 2026-09-24.

Libraries

Not in the archive: the export carries no per-task library table, so there is nothing to show at snapshot 2025-07-28.

Datasets archive 2025-07-28

6 datasets whose archive record lists this task, ordered by the archive's paper count.

Subtasks archive 2025-07-28

1 subtask in the archive's task tree.

Most implemented papers archive 2025-07-28

30 shown of 81 papers with code (204 tagged with this task in all), ordered by repositories listed in the archive, not by stars (the archive holds no stars, so PwC's “Social” and “Latest” sorts cannot be reproduced). Papers without a page here are shown as plain text.

• Scheduled Sampling for Sequence Prediction with Recurrent Neural Networks
  9 Jun 2015 9 repositories listed Syntology ran 0 of 8 samples · 8 unverified
  Recurrent Neural Networks can be trained to produce sequences of tokens given some input, as exemplified by recent results in machine translation and image captioning.
• Grammar as a Foreign Language
  23 Dec 2014 7 repositories listed Syntology ran 0 of 17 samples · 17 unverified
  Syntactic constituency parsing is a fundamental problem in natural language processing and has been the subject of intensive research and engineering for decades.
• Recurrent Neural Network Grammars
  25 Feb 2016 6 repositories listed Syntology ran 6 of 10 samples · 4 unverified · 6 pointer-only (licence)
  We introduce recurrent neural network grammars, probabilistic models of sentences with explicit phrase structure.
• Constituency Parsing with a Self-Attentive Encoder
  2 May 2018 5 repositories listed Syntology ran 0 of 14 samples · 14 unverified
  We demonstrate that replacing an LSTM encoder with a self-attentive architecture can lead to improvements to a state-of-the-art discriminative constituency parser.
• Multilingual Constituency Parsing with Self-Attention and Pre-Training
  31 Dec 2018 4 repositories listed Syntology ran 3 of 28 samples · 25 unverified · 3 pointer-only (licence)
  We show that constituency parsing benefits from unsupervised pre-training across a variety of languages and a range of pre-training conditions.
• Strongly Incremental Constituency Parsing with Graph Neural Networks
  27 Oct 2020 3 repositories listed Syntology ran 2 of 5 samples · 3 unverified
  Based on our transition system, we develop a strongly incremental parser.
• Generalizing Natural Language Analysis through Span-relation Representations
  10 Nov 2019 3 repositories listed
  Natural language processing covers a wide variety of tasks predicting syntax, semantics, and information content, and usually each type of output is generated with specially designed architectures.
• Unsupervised Latent Tree Induction with Deep Inside-Outside Recursive Autoencoders
  3 Apr 2019 3 repositories listed Syntology ran 4 of 16 samples · 12 unverified
  We introduce deep inside-outside recursive autoencoders (DIORA), a fully-unsupervised method for discovering syntax that simultaneously learns representations for constituents within the induced tree.
• Grammar-Constrained Decoding for Structured NLP Tasks without Finetuning
  23 May 2023 2 repositories listed Syntology ran 2 of 14 samples · 12 unverified
  In this work, we demonstrate that formal grammars can describe the output space for a much wider range of tasks and argue that GCD can serve as a unified framework for structured NLP tasks in general.
• Challenges to Open-Domain Constituency Parsing
  1 May 2022 2 repositories listed
  Neural constituency parsers have reached practical performance on news-domain benchmarks.
• StructFormer: Joint Unsupervised Induction of Dependency and Constituency Structure from Masked Language Modeling
  1 Dec 2020 2 repositories listed
  There are two major classes of natural language grammar -- the dependency grammar that models one-to-one correspondences between words and the constituency grammar that models the assembly of one or several corresponded…
• Converting the Point of View of Messages Spoken to Virtual Assistants
  6 Oct 2020 2 repositories listed
  CopyNet was the most natural, with a relative perplexity of 1.
• Fast and Accurate Neural CRF Constituency Parsing
  9 Aug 2020 2 repositories listed Syntology ran 3 of 3 samples · 0 unverified
  Estimating probability distribution is one of the core issues in the NLP field.
• Rethinking Self-Attention: Towards Interpretability in Neural Parsing
  10 Nov 2019 2 repositories listed Syntology ran 1 of 3 samples · 2 unverified · 3 pointer-only (licence)
  Finally, we find that the Label Attention heads learn relations between syntactic categories and show pathways to analyze errors.
• Tetra-Tagging: Word-Synchronous Parsing with Linear-Time Inference
  22 Apr 2019 2 repositories listed
  We present a constituency parsing algorithm that, like a supertagger, works by assigning labels to each word in a sentence.
• Straight to the Tree: Constituency Parsing with Neural Syntactic Distance
  11 Jun 2018 2 repositories listed
  In this work, we propose a novel constituency parsing scheme.
• YellowFin and the Art of Momentum Tuning
  12 Jun 2017 2 repositories listed Syntology ran 0 of 1 samples · 1 unverified
  We revisit the momentum SGD algorithm and show that hand-tuning a single learning rate and momentum makes it competitive with Adam.
• Automatic Extraction of Clausal Embedding Based on Large-Scale English Text Data
  16 Jun 2025 1 repository listed
  Finally, we present a large-scale dataset of naturally-occurring English embedded clauses which we have extracted from the open-source corpus Dolma using our extraction tool.
• Improving Unsupervised Constituency Parsing via Maximizing Semantic Information
  3 Oct 2024 1 repository listed Syntology ran 1 of 1 samples · 0 unverified · 1 pointer-only (licence)
  In this paper, we introduce a novel objective for training unsupervised parsers: maximizing the information between constituent structures and sentence semantics (SemInfo).
• Structural Optimization Ambiguity and Simplicity Bias in Unsupervised Neural Grammar Induction
  23 Jul 2024 1 repository listed
  Neural parameterization has significantly advanced unsupervised grammar induction.
• To be Continuous, or to be Discrete, Those are Bits of Questions
  12 Jun 2024 1 repository listed
  In this paper, we investigate the feasibility of further introducing it to the output side, aiming to allow models to output binary labels instead.
• Tree-Averaging Algorithms for Ensemble-Based Unsupervised Discontinuous Constituency Parsing
  29 Feb 2024 1 repository listed Syntology ran 8 of 10 samples · 2 unverified · 10 pointer-only (licence)
  We address unsupervised discontinuous constituency parsing, where we observe a high variance in the performance of the only previous model in the literature.
• Structured Tree Alignment for Evaluation of (Speech) Constituency Parsing
  21 Feb 2024 1 repository listed Syntology ran 3 of 3 samples · 0 unverified
  We present the structured average intersection-over-union ratio (STRUCT-IOU), a similarity metric between constituency parse trees motivated by the problem of evaluating speech parsers.
• Sketch-Guided Constrained Decoding for Boosting Blackbox Large Language Models without Logit Access
  18 Jan 2024 1 repository listed Syntology ran 2 of 7 samples · 5 unverified · 7 pointer-only (licence)
  This paper introduces sketch-guided constrained decoding (SGCD), a novel approach to constrained decoding for blackbox LLMs, which operates without access to the logits of the blackbox LLM.
• Multistage Collaborative Knowledge Distillation from a Large Language Model for Semi-Supervised Sequence Generation
  15 Nov 2023 1 repository listed Syntology ran 5 of 5 samples · 0 unverified · 5 pointer-only (licence)
  In this paper, we present the discovery that a student model distilled from a few-shot prompted LLM can commonly generalize better than its teacher to unseen examples on such tasks.
• LLM-enhanced Self-training for Cross-domain Constituency Parsing
  5 Nov 2023 1 repository listed
  Our experimental results demonstrate that self-training for constituency parsing, equipped with an LLM, outperforms traditional methods regardless of the LLM's performance.
• Simple Hardware-Efficient PCFGs with Independent Left and Right Productions
  23 Oct 2023 1 repository listed Syntology ran 3 of 3 samples · 0 unverified · 3 pointer-only (licence)
  Scaling dense PCFGs to thousands of nonterminals via a low-rank parameterization of the rule probability tensor has been shown to be beneficial for unsupervised parsing.
• DepNeCTI: Dependency-based Nested Compound Type Identification for Sanskrit
  14 Oct 2023 1 repository listed
  This work introduces the novel task of nested compound type identification (NeCTI), which aims to identify nested spans of a multi-component compound and decode the implicit semantic relations between them.
• Ensemble Distillation for Unsupervised Constituency Parsing
  3 Oct 2023 1 repository listed Syntology ran 16 of 22 samples · 6 unverified · 22 pointer-only (licence)
  We investigate the unsupervised constituency parsing task, which organizes words and phrases of a sentence into a hierarchical structure without using linguistically annotated data.
• Approximating CKY with Transformers
  3 May 2023 1 repository listed
  We investigate the ability of transformer models to approximate the CKY algorithm, using them to directly predict a sentence's parse and thus avoid the CKY algorithm's cubic dependence on sentence length.

Syntology lines on 18 of the papers shown; no Syntology record for the others (a paper without an arXiv id cannot be joined to the graph, and absence from the graph layer is not a recorded non-run). “Ran” means the sample executed on a synthesized fixture, not that the paper's result was reproduced. Read from the graph 2026-09-24.