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Psychology

Reproducibility of individual effect sizes in meta-analyses in psychology

Esther Maassen et al. (2020)

Published
May 27, 2020
Journal
PLOS ONE · Vol. 15 · No. 5
DOI
10.1371/journal.pone.0233107

At a Glance

In half of the meta-analyses, there isn’t enough data for a proper verification.

Summary

The authors attempted to reproduce 500 primary study effect sizes from 33 randomly selected psychological meta-analyses. Only ~55% were fully reproducible. The rest were incomplete (11%), incorrect (14%), or ambiguous (19%). In 30 of 33 meta-analyses, at least some effect sizes contained errors. The good news: when they recalculated meta-analytic results with corrected effect sizes, the overall conclusions mostly didn't change (significance of pooled effects was preserved). The bad news: that's partly because errors were random rather than systematic.

Method Snapshot

recalculation from the primary sources

Background

basic statistics

Half the effect sizes in psychology meta-analyses can't be reproduced from the primary papers. Sleep well.

ES