Cited by 85Meta-analysis and systematic reviewsPsychology Research and BibliometricsStatistical Methods in Epidemiology

Calculating statistical power for meta-analysis using metapower

Open access
Griffin, Jason W.·2021·The Quantitative Methods for Psychology

Abstract

Meta-analysis is an influential evidence synthesis technique that summarizes a body of research.Though impactful, meta-analyses fundamentally depend on the literature being sufficiently large to generate meaningful conclusions.Power analysis plays an important role in determining the number of studies required to conduct a substantive meta-analysis.Despite this, power analysis is rarely conducted or reported in published meta-analyses.A significant barrier to the widespread implementation of power analysis is the lack of available and accessible software for calculating statistical power for meta-analysis.In this paper, I provide an introduction to power analysis and present a practical tutorial for calculating statistical power using the R package metapower.The main functionality includes computing statistical power for summary effect sizes, tests of homogeneity, categorical moderator analysis, and subgroup analysis.This software is free, easy-to-use, and can be integrated into a continuous work flow with other meta-analysis packages in R.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.20982/tqmp.17.1.p024

Cites

24 of 24 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • At least seven studies are required to achieve 80% power at an α of .05 for the estimated small-to-medium effect size (Hedge's g = .35) and average sample size (N = 39).

    “The analysis suggests that at least seven studies are required to achieve 80% power at an α of .05.”

    From Menstrual cycle effects on cognitive performance: A meta-analysis (2025) · cites this paper as [73]

    The Number of Studies section (page unavailable) explains that the number needed for adequate meta-analytic power depends on effect size, study size, error probability, test type, and model assumptions. The Summary effect size section uses 80% as a conventional power target. Neither section reports that seven studies suffice for the stated effect size and sample size; the paper’s worked example uses different inputs. (LLM, conf=0.82)

    Experimental — accuracy not yet measured

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Research works printed but not linked: 2

  1. [23]23. Valentine, J. C., Pigott, T. D., & Rothstein, H. R. (2009). How many studies do you need? Journal of Educational and Behavioral Statistics, 35(2), 215-247. doi:10.3102/ 1076998609346961
  2. [24]24. Griffin, J. W. (2021). Calculating statistical power for meta-analysis using metapower. The Quantitative Methods for Psy- chology, 17(1), 24-39. doi:10.20982/tqmp.17.1.p024

Cited by

Sorted by citations

Authors
Griffin, J. W.
Affiliations
Pennsylvania State University (US)
Corresponding author
Griffin, Jason W.
Venue
The Quantitative Methods for Psychology
Published
2021-03-01
Volume
17
Issue
1
Pages
24-39
ISSN
2292-1354 (ISSN-L)
OpenAlex
W3138345420
Cited by
84
References
24
Citations by year
2026: 22 · 2025: 17 · 2024: 13 · 2023: 18 · 2022: 9 · 2021: 5
FWCI
6.52
Type
journal article
Language
en
Open access
Locations
  • The Quantitative Methods for Psychology (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Topics
  • Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Meta-analysis and systematic reviews
  • Social Sciences › Psychology › Experimental and Cognitive Psychology › Psychology Research and Bibliometrics
  • Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Epidemiology
Keywords
statistical power, power analysis, meta-analysis, R package, sample size determination, heterogeneity testing, subgroup analysis, meta-analysis software

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review