Testing for reviewer anchoring in peer review: A randomized controlled trial

Our randomized controlled trial consists of 108 researchers as participants. First, we find that our intervention was successful at creating a difference in perceived paper quality between the flawed and corrected versions: Using a permutation test with the Mann-Whitney U statistic, we find that the experimental group's initial scores are lower than the control group's scores in both the Evaluation category (Vargha-Delaney A = 0.64, p = 0.0096) and Overall score (A = 0.59, p = 0.058). Next, we test for anchoring by comparing the experimental group's revised scores with the control group's scores. We find no significant evidence of anchoring in either the Overall (A = 0.50, p = 0.61) or Evaluation category (A = 0.49, p = 0.61). The Mann-Whitney U represents the number of individual pairwise comparisons across groups in which the value from the specified group is stochastically greater, while the Vargha-Delaney A is the normalized version in [0, 1].