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Record W1706534725

Recognizing named entities in biomedical texts

2008· dissertation· en· W1706534725 on OpenAlexaff
Baohua Gu

Bibliographic record

VenueSummit (Simon Fraser University) · 2008
Typedissertation
Languageen
FieldBiochemistry, Genetics and Molecular Biology
TopicBiomedical Text Mining and Ontologies
Canadian institutionsSimon Fraser University
Fundersnot available
KeywordsComputer scienceNamed-entity recognitionBiomedical text miningArtificial intelligenceNatural language processingWord (group theory)Domain (mathematical analysis)Named entityText miningTask (project management)Linguistics
DOInot available

Abstract

fetched live from OpenAlex

Named Entities (NEs) in biomedical text refer to objects that are of interest to biomedical researchers, such as proteins and genes. Accurately identifying them is important for Biomedical Natural Language Processing (BioNLP). Focusing on biomedical named entity recognition (BioNER), this thesis presents a number of novel results on the following topics of this area. First, we study whether corpus based statistical learning methods, currently dominant in BioNER, would achieve close-to-human performance by using larger corpora for training. We find that a significantly larger corpus is required to achieve a performance significantly higher than the state-of-the-art obtained on the GENIA corpus. This finding suggests the hypothesis is not warranted. Second, we address the issue of nested NEs and propose a level-by-level method that learns a separate NER model for each level of the nesting. We show that this method works well for both nested NEs and non-nested NEs. Third, we propose a method that builds NEs on top of base NP chunks, and examine the associated benefits as well as problems. Our experiments show that this method, though inferior to statistical word based approaches, has the potential to outperform them, provided that domain-specific rules can be designed to determine NE boundaries based on NP chunks. Fourth, we present a method to do BioNER in the absence of annotated corpora. It uses an NE dictionary to label sentences, and then uses these partially labeled sentences to iteratively train an SVM model in the manner of semi-supervised learning. Our experiments validate the effectiveness of the method. Finally, we explore BioNER in Chinese text, an area that has not been studied by previous work. We train a character-based CRF model on a small set of manually annotated Chinese biomedical abstracts. We also examine the features usable for the model. Our evaluation suggests that corpus-based statistical learning approaches hold promise for this particular task. All the proposed methods are novel and have applicability beyond the NE types and the languages considered here, and beyond the BioNER task itself.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Not applicable · Consensus signal: Not applicable
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.489
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0010.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.014
GPT teacher head0.235
Teacher spread0.221 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

Study designNot applicable
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations1
Published2008
Admission routes1
Has abstractyes

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