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Record W2049721389 · doi:10.2527/jas.2009-1908

Statistical power calculations: Comment

2009· letter· en· W2049721389 on OpenAlexaff
Les Leventhal

Bibliographic record

VenueJournal of Animal Science · 2009
Typeletter
Languageen
FieldMathematics
TopicStatistical Methods in Clinical Trials
Canadian institutionsUniversity of Manitoba
Fundersnot available
KeywordsNull (SQL)Statistical powerNull hypothesisPower (physics)MathematicsPhenomenonConditional probabilityStatistical hypothesis testingStatisticsNull modelComputer sciencePhysicsCombinatoricsData miningThermodynamics

Abstract

fetched live from OpenAlex

Power analysis is often used to interpret nonsignificant results (NS). It is a 2-step process: Step 1: Calculate the power of the NS test. Step 2: Use the calculated power to decide whether the NS occurred because (a) the phenomenon was not present or (b) the phenomenon was present but the test had insufficient power to detect it. If power is high, one accepts: (a) the phenomenon was not present. If power is low, one cannot decide between (a) and (b): the NS is not interpretable. This reasoning has minor variations to accommodate the effect size selected for the power analysis. Lenth (2007) argued against using power to interpret NS. Lenth began with an incorrect definition of power. Power is the probability of rejecting the null when the null is false. Power is a conditional probability. The condition is “when the null is false.” Lenth (2007) defined power as “the probability of obtaining a statistically significant result.” This is not a conditional probability and is not correct. Using Lenth's phrasing, power, correctly defined, would be “the probability of obtaining a statistically significant result when the null is false.”

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)0.077
metaresearch head score (Gemma)0.437
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesMetaresearch
Consensus categoriesnone
DomainCandidate signal: Methods · Consensus signal: none
Study designCandidate signal: Not applicable · Consensus signal: Not applicable
GenreCandidate signal: Commentary · Consensus signal: Commentary
Teacher disagreement score0.923
Threshold uncertainty score0.409

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0770.437
Meta-epidemiology (narrow)0.0020.001
Meta-epidemiology (broad)0.0020.003
Bibliometrics0.0020.002
Science and technology studies0.0030.013
Scholarly communication0.0050.007
Open science0.0070.004
Research integrity0.0340.058
Insufficient payload (model declined to judge)0.0130.017

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 head0.509
GPT teacher head0.583
Teacher spread0.074 · 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.

Study designNot applicable
DomainMethods
GenreCommentary

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

Citations5
Published2009
Admission routes1
Has abstractyes

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