Papers › Named Entity Recognition with Bidirectional LSTM-CNNs

Named Entity Recognition with Bidirectional LSTM-CNNs

26 Nov 2015TACL 2016 1arXiv:1511.08308archive 2025-07-28

Jason P. C. Chiu, Eric Nichols

Named entity recognition is a challenging task that has traditionally required large amounts of knowledge in the form of feature engineering and lexicons to achieve high performance. In this paper, we present a novel neural network architecture that automatically detects word- and character-level features using a hybrid bidirectional LSTM and CNN architecture, eliminating the need for most feature engineering. We also propose a novel method of encoding partial lexicon matches in neural networks and compare it to existing approaches. Extensive evaluation shows that, given only tokenized text and publicly available word embeddings, our system is competitive on the CoNLL-2003 dataset and surpasses the previously reported state of the art performance on the OntoNotes 5.0 dataset by 2.13 F1 points. By using two lexicons constructed from publicly-available sources, we establish new state of the art performance with an F1 score of 91.62 on CoNLL-2003 and 86.28 on OntoNotes, surpassing systems that employ heavy feature engineering, proprietary lexicons, and rich entity linking information.

PaperPDFConference PDFCodeCode Syntology ran

In Syntology Open this paper in Syntology's Atlas, the map of the papers in Syntology's graph and their citations.

For agents, Syntology's MCP tool lists every function and class Syntology harvested from this paper and whether it ran (how to connect): get_harvested_code_for_paper(arxiv_id="1511.08308")

Code

Syntology Ran 4 of 9 code samples harvested from 2 repositories linked to this paper; 5 have no recorded run. Of those that ran: 2 ran · honoured contract; 2 ran · our draft was wrong.

By repository: community (archive-listed): 8 samples from 2 repositories, 3 ran; 1 identical to code first harvested elsewhere. The run record, sample by sample. “Ran” means executed on a synthesized input, not that the code is correct or reproduces the paper.

14 repositories listed; official and paper-mentioned ones first.

epwalsh/pytorch-crf mentioned on GitHubpytorchMIT report
flairNLP/flair mentioned on GitHubpytorchNOASSERTION report
niccolot/NER_biLSTM-CNN mentioned on GitHubtf report
osamadev/NER_Using_Spacy mentioned on GitHub report
rikhuijzer/nlu_datasets mentioned on GitHub report
shakimov/SimpleQA-NER mentioned on GitHubtfGPL-3.0 report
zalandoresearch/flair mentioned on GitHubpytorchNOASSERTION report

Repository list and official/mentioned flags are the archive's, frozen 2025-07-28. Reachability, where shown, is from one Syntology probe window (2026-09-16 to 2026-09-18); repositories not probed show nothing. GitHub stars are not tracked.

Code Syntology ran Syntology

9 samples harvested; 4 ran; 2 honoured the contract we drafted; 5 have no recorded run. Read from Syntology's graph 2026-09-24; that is when this build read the record, not when the samples ran.

2ran · honoured contract
2ran · our draft was wrong
5unverified

Licence: 4 of the 9 samples are pointer only, meaning Syntology does not serve that copy's text. This page shows no code text for any sample; each one links to its file in the repository.

Harvested from 2 repositories linked to this paper, official or community; each sample names its own and says which. Some samples are identical code Syntology first harvested from another repository; for those, this paper's copy is not located and its licence is not recorded. “Ran” means the sample executed on a synthesized input. It does not mean the output is correct, and nothing here reproduces the paper's results. “Honoured” and “violated” refer to a contract Syntology drafted from the code itself; “our draft was wrong” and “fixture could not drive it” are failures of Syntology's instrument, not of the code.

Each sample ends with its code_sha256, Syntology's identity for that exact code. An agent fetches the stored sample with Syntology's MCP tool get_code(code_sha256="…") (how to connect); click an identity to copy that call.

Repository labels, per sample. official repository: The archive marks this repository official for the paper. named in the paper: The archive records that the paper mentions this repository; it is not marked official. community (archive-listed): In the archive's code links for this paper, not marked official and not recorded as mentioned in the paper. found in paper text by Syntology: Syntology found this repository in the paper's own text; whether it is the authors' implementation is not asserted. community: Not in the archive's code links for this paper; a community repository Syntology harvested. Samples from a repository marked official are listed first. Licence labels name the repository's licence as recorded at harvest. “Pointer only” means Syntology does not serve that copy's text, for one of four reasons: no licence file was found; the licence was not identified; the licence is recorded as permissive but that copy's record is not marked cleared; or the licence is outside the permissive list Syntology serves text under (MIT, Apache-2.0, BSD and similar). Some licences outside that list permit redistribution, such as WTFPL, and GPL-3.0 under its conditions; they are simply not on the list. Hover a licence label for the reason. File links open the file on GitHub at the default branch, which may have changed since the harvest.

get_casing niccolot/NER_biLSTM-CNN/preprocessing.py community (archive-listed) ran · honoured contract no licence file found · pointer only · d92a205fe8492607 · report
get_char_info niccolot/NER_biLSTM-CNN/preprocessing.py community (archive-listed) ran · our draft was wrong no licence file found · pointer only · d17be84f16bfcdb3 · report
get_lines niccolot/NER_biLSTM-CNN/preprocessing.py community (archive-listed) ran · our draft was wrong no licence file found · pointer only · cd6e630e323645e1 · report
compute_f1 mxhofer/Named-Entity-Recognition-BidirectionalLSTM-CNN-CoNLL/validation.py community (archive-listed) unverified MIT (permissive) · e7fa1b4511321cb3 · report
compute_precision mxhofer/Named-Entity-Recognition-BidirectionalLSTM-CNN-CoNLL/validation.py community (archive-listed) unverified MIT (permissive) · f5cc0f3470ea30e7 · report
createEqualBatches mxhofer/Named-Entity-Recognition-BidirectionalLSTM-CNN-CoNLL/prepro.py community (archive-listed) unverified MIT (permissive) · 3e984024e0b78214 · report
getCasing mxhofer/Named-Entity-Recognition-BidirectionalLSTM-CNN-CoNLL/prepro.py community (archive-listed) unverified MIT (permissive) · 6d0b5dd684a16ec8 · report
readfile mxhofer/Named-Entity-Recognition-BidirectionalLSTM-CNN-CoNLL/prepro.py community (archive-listed) unverified MIT (permissive) · 5b7a20a3a09ffb47 · report
log_sum_exp identical code first harvested elsewhere ran · honoured contract fingerprinted licence of this copy not recorded · d4329236872658c9 · report

Tasks

Entity LinkingFeature EngineeringNamed Entity RecognitionNamed Entity Recognition (NER)Word Embeddings

Results from the paper archive 2025-07-28

TaskDatasetModelMetricValueRank at snapshotLeaderboardReport
Named Entity Recognition (NER) CoNLL 2003 (English) Bi-LSTM-CNN F1 91.62 #58 of 73 Archive leaderboard report
Named Entity Recognition (NER) Ontonotes v5 (English) Chiu and Nichols (2016) F1 86.19 #27 of 28 Archive leaderboard report

Ranks are positions in the archive's leaderboards as they stood at the 2025-07-28 snapshot. Results published since then are not among these rows, so a rank here is not a current standing.

Methods

Introduced by this paper: CNN BiLSTM

BiLSTMCNN BiLSTMConvolutionLSTMSigmoid ActivationTanh Activation

Report a problem or propose a change · a person checks every report against the paper or source before anything changes; decisions are listed on /corrections