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Record W1970217629 · doi:10.5784/18-0-183

Omitting correlated variables

2014· article· en· W1970217629 on OpenAlexaff
Larry Jenkins, Matthew E. Anderson

Bibliographic record

VenueOrion/ORiON · 2014
Typearticle
Languageen
FieldDecision Sciences
TopicEfficiency Analysis Using DEA
Canadian institutionsRoyal Military College of Canada
Fundersnot available
KeywordsPrincipal component analysisVariance (accounting)Variable (mathematics)Covariance matrixCovariance and correlationVariablesComputer scienceDesign matrixPrincipal (computer security)StatisticsCovarianceExplained variationMatrix (chemical analysis)Data MatrixMeasure (data warehouse)ConditioningMathematicsData miningRegression analysisRandom variableSum of normally distributed random variables

Abstract

fetched live from OpenAlex

Data collected on the physical, biological or man-made world are often highly correlated, posing the question of whether fewer variables would contain almost as much information. A crude solution is simply to look at the Pearson correlation matrix and omit one of a pair of highly correlated variables. A more systematic method is to condition on one or more variables, and observe the resulting partial covariance matrix. If the variables have little variance after the conditioning, then the conditioning variables contain most of the information of all the original variables. Paralleling the usual tests applied in judging how many principal components are sufficient to represent all the data, we can use the amount of variance explained by the conditioning variable (s), as a measure of information content. The paper references earlier work in this area, explains the computation and includes examples using published data sets. The approach is found to be highly competitive with using principal components, and has the obvious advantage over principal components of simply omitting some of the original variables from further consideration. The method has been coded in Visual-Basic add-ins to an Excel spreadsheet.

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)0.015
metaresearch head score (Gemma)0.100
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 score0.015
Threshold uncertainty score0.081

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0150.100
Meta-epidemiology (narrow)0.0030.001
Meta-epidemiology (broad)0.0030.003
Bibliometrics0.0040.007
Science and technology studies0.0020.002
Scholarly communication0.0050.005
Open science0.0030.004
Research integrity0.0010.004
Insufficient payload (model declined to judge)0.0120.007

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 head0.043
GPT teacher head0.331
Teacher spread0.288 · 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

Citations1
Published2014
Admission routes1
Has abstractyes

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