biostudies-literatureUnknown5Steegen SAccording to the crowd within effect, the average of two estimates from one person tends to be more accurate than a single estimate of that person. The effect implies that the well documented wisdom of the crowd effect-the crowd's average estimate tends to be more accurate than the individual estimates-can be obtained within a single individual. In this paper, we performed a high-powered, pre-registered replication study of the original experiment. Our replication results are evaluated with the traditional null hypothesis significance testing approach, as well as with effect sizes and their confidence intervals. We adopted a co-pilot approach, in the sense that all analyses were performed independently by two researchers using different analysis software. Moreover, we report Bayes factors Frontiers in psychology786https://www.ebi.ac.uk/biostudies/studies/S-EPMC4112915biostudies-literatureMeasuring the crowd within again: a pre-registered replication study.PMC4112915Steegen SDewitte LVanpaemel WTuerlinckx FfalseMeasuring the crowd within again: a pre-registered replication study.According to the crowd within effect, the average of two estimates from one person tends to be more accurate than a single estimate of that person. The effect implies that the well documented wisdom of the crowd effect-the crowd's average estimate tends to be more accurate than the individual estimates-can be obtained within a single individual. In this paper, we performed a high-powered, pre-registered replication study of the original experiment. Our replication results are evaluated with the traditional null hypothesis significance testing approach, as well as with effect sizes and their confidence intervals. We adopted a co-pilot approach, in the sense that all analyses were performed independently by two researchers using different analysis software. Moreover, we report Bayes factors 2014-01-01T00:00:00Z20142025-04-04T20:50:24.013Z2019-03-27T01:32:55ZS-EPMC41129152512050510.3389/fpsyg.2014.00786