MétaCan
Menu
← Back to cohort
Record W4253177523 · doi:10.31219/osf.io/wr93f

Z-Curve

2017· preprint· en· W4253177523 on OpenAlexafffund
Ulrich Schimmack, Jerry Brunner

Bibliographic record

Venuenot available
Typepreprint
Languageen
FieldDecision Sciences
TopicMeta-analysis and systematic reviews
Canadian institutionsUniversity of Toronto
FundersSocial Sciences and Humanities Research Council of Canada
KeywordsReplication (statistics)Statistical powerSelection (genetic algorithm)StatisticsCredibilityPower (physics)EconometricsSelection biasPsychologyStatistical significanceComputer scienceMathematicsArtificial intelligencePhysicsPolitical science

Abstract

fetched live from OpenAlex

In recent years, the replicability of original findings published in psychology journals has been questioned. A key concern is that selection for significance inflates observed effect sizes and observed power. If selection bias is severe, replication studies are unlikely to reproduce a significant result. We introduce z-curve as a new method that can estimate the average true power for sets of studies that are selected for significance. We compare this method with p-curve, which has been used for the same purpose. Simulation studies show that both methods perform well when all studies have the same power, but p-curve overestimates power if power varies across studies. Based on these findings, we recommend z-curve to estimate power for sets of studies that are heterogeneous and selected for significance. Application of z-curve to various datasets suggests that the average replicability of published results in psychology is approximately 50%, but there is substantial heterogeneity and many psychological studies remain underpowered and are likely to produce false negative results. To increase replicability and credibility of published results it is important to reduce selection bias and to increase statistical power.

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)0.062
metaresearch head score (Gemma)0.354
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesMetaresearch
Consensus categoriesnone
DomainCandidate signal: Methods · Consensus signal: none
Study designCandidate signal: Simulation or modeling · Consensus signal: none
GenreCandidate signal: Methods · Consensus signal: Methods
Teacher disagreement score0.938
Threshold uncertainty score0.000

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0620.354
Meta-epidemiology (narrow)0.0030.001
Meta-epidemiology (broad)0.0030.006
Bibliometrics0.0130.011
Science and technology studies0.0020.004
Scholarly communication0.0090.009
Open science0.0040.005
Research integrity0.0050.005
Insufficient payload (model declined to judge)0.0360.013

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 head0.933
GPT teacher head0.628
Teacher spread0.305 · 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 designSimulation or modeling
DomainMethods
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

Citations8
Published2017
Admission routes2
Has abstractyes

Explore more

Same topicMeta-analysis and systematic reviews→French-language works237,207→