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Record W2047034391 · doi:10.1081/sta-200045867

Robust Reduced Rank Mixture Discriminant Analysis

2005· article· en· W2047034391 on OpenAlexaff
Shaheena Bashir, E. M. Carter

Bibliographic record

VenueCommunication in Statistics- Theory and Methods · 2005
Typearticle
Languageen
FieldMathematics
TopicAdvanced Statistical Methods and Models
Canadian institutionsUniversity of Guelph
Fundersnot available
KeywordsLinear discriminant analysisMathematicsOutlierRank (graph theory)Optimal discriminant analysisPattern recognition (psychology)CovarianceMultiple discriminant analysisStatisticsSubspace topologyMixture modelGaussianDiscriminantKernel Fisher discriminant analysisCovariance matrixArtificial intelligenceComputer scienceCombinatoricsChemistry

Abstract

fetched live from OpenAlex

In the case of a large number of feature vector variables, using multivariate Gaussian mixture models, discrimination in a reduced subspace is studied, generalizing Hastie and Tibshirani's (1996) work, to a situation in which the outliers are present in the data. In the case of the Gaussian Mixture models, the reduced rank discriminant analysis is equivalent to the weighted rank k linear discriminant analysis (LDA). The reduced rank solution in the mixtures of multivariate Gaussian models was obtained from the full rank robust mixture solution. The classification in the new dimensions was compared with the discriminant analysis approach based on the original coordinates, using robust S-estimators. In most of the cases, the robust reduced rank mixture discriminant analysis (mda) performed better for the test data. However, for the case of common component covariance being diagonal, the robust reduced rank mixture discriminant analysis performed better than the robust full rank mixture discriminant analysis producing smaller errors in classification.

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 machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.003
metaresearch head score (Gemma)0.007
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Theoretical or conceptual · Consensus signal: none
GenreCandidate signal: Methods · Consensus signal: Methods
Teacher disagreement score0.003
Threshold uncertainty score0.015

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0030.007
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0020.002
Bibliometrics0.0020.002
Science and technology studies0.0000.001
Scholarly communication0.0020.001
Open science0.0010.001
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0030.002

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 head0.159
GPT teacher head0.501
Teacher spread0.342 · 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 source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designTheoretical or conceptual
Domainnot available
GenreMethods

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

Citations3
Published2005
Admission routes1
Has abstractyes

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