A Review of Multisite Replication Projects in Social Psychology: Is It Viable to Sustain Any Confidence in Social Psychology's Knowledge Base?

Multisite (multilab/many-lab) replications have emerged as a popular way of verifying prior research findings, but their record in social psychology has prompted distrust of the field and a sense of crisis. We review all 36 multisite social-psychology replications (plus three articles reporting multiple ministudies). We start by assuming that both the original and the multisite replications were conducted in honest and diligent fashion, despite often yielding different conclusions. Four of the 36 (11%) were clearly successful in terms of providing significant support for the original hypothesis, and five others (14%) had mixed results. The remaining 27 (75%) were failures. Multiple explanations for the generally poor record of replications are considered, including the possibility that the original hypothesis was wrong; operational failure; low engagement of participants; and bias toward failure. The relevant evidence is assessed as well. There was evidence for each of the possibilities listed above, with low engagement emerging as a widespread problem (reflected in high rates of discarded data and weak manipulation checks). The few procedures with actual interpersonal interaction fared much better than others. We discuss implications in relation to manipulation checks, effect sizes, and impact on the field and offer recommendations for improving future multisite projects.

Many Labs 5: Testing Pre-Data-Collection Peer Review as an Intervention to Increase Replicability

Replication studies in psychological science sometimes fail to reproduce prior findings. If these studies use methods that are unfaithful to the original study or ineffective in eliciting the phenomenon of interest, then a failure to replicate may be a failure of the protocol rather than a challenge to the original finding. Formal pre-data-collection peer review by experts may address shortcomings and increase replicability rates. We selected 10 replication studies from the Reproducibility Project: Psychology (RP:P; Open Science Collaboration, 2015) for which the original authors had expressed concerns about the replication designs before data collection; only one of these studies had yielded a statistically significant effect ( p < .05). Commenters suggested that lack of adherence to expert review and low-powered tests were the reasons that most of these RP:P studies failed to replicate the original effects. We revised the replication protocols and received formal peer review prior to conducting new replication studies. We administered the RP:P and revised protocols in multiple laboratories (median number of laboratories per original study = 6.5, range = 3–9; median total sample = 1,279.5, range = 276–3,512) for high-powered tests of each original finding with both protocols. Overall, following the preregistered analysis plan, we found that the revised protocols produced effect sizes similar to those of the RP:P protocols (Δ r = .002 or .014, depending on analytic approach). The median effect size for the revised protocols ( r = .05) was similar to that of the RP:P protocols ( r = .04) and the original RP:P replications ( r = .11), and smaller than that of the original studies ( r = .37). Analysis of the cumulative evidence across the original studies and the corresponding three replication attempts provided very precise estimates of the 10 tested effects and indicated that their effect sizes (median r = .07, range = .00–.15) were 78% smaller, on average, than the original effect sizes (median r = .37, range = .19–.50).