In the Reproducibility Project, effects that were successfully replicated were generally smaller or weaker than the effects reported in the original studies.
Notes on verification
Confirmed by the original OSF Reproducibility Project 2015 report, Wikipedia summary, BPS Research Digest, and independent secondary analyses (PLOS ONE, Behavior Research Methods) all showing replicated effect sizes were roughly half the magnitude of original studies. [cascade flags: wikipedia_dropped_other_sources_exist | tier=unverified indep_score=0.3 clusters=2 claim_tier=notable] [rescored 2026-09-15: curated origin-host map (PR #65); unclassified hosts no longer scored as aggregators]
Sources
- A reproducibility crisis? - American Psychological Association (seed:psychology_and_neuroscience)
- https://www.bps.org.uk/research-digest/what-happened-when-psychologists-tried-replicate-100-previously-published-findings (corroboration)
- https://osf.io/ezcuj/ (corroboration)