Volunteer researchers selected a study to replicate from a quasi-random sample of studies published in three prominent journals from the 2008 publication year. Several strategies were followed to maximize the quality – and hence diagnosticity -- of replication attempts. Each replication used sample sizes that achieved at least 80% power to detect an effect as large as the effect reported in the original article. Most studies achieved power levels of 90% or higher. Replication teams contacted original authors to acquire original materials and any missing methodological details required for a fair replication attempt. In addition, each team drafted a replication protocol outlining the procedure and data-analysis plan. The protocol followed a standard template and was sent to original authors for review. Any design discrepancies identified by the original authors were addressed or documented. Prior to data collection, the final replication protocol was registered and added to an online repository.