Implicit versus Explicit First Impressions in Performance-Based Assessment: Will Raters Overcome Their First Impressions When Learner Performance Changes?

First impressions can influence rater-based judgments but their contribution to rater bias is unclear. Research suggests raters can overcome first impressions in experimental exam contexts with explicit first impressions, but these findings may not generalize to a workplace context with implicit first impressions. The study had two aims. First, to assess if first impressions affect raters' judgments when workplace performance changes. Second, whether explicitly stating these impressions affects subsequent ratings compared to implicitly-formed first impressions. Physician raters viewed six videos where learner performance either changed (Strong to Weak or Weak to Strong) or remained consistent. Raters were assigned two groups. Group one (n = 23, Explicit) made a first impression global rating (FIGR), then scored learners using the Mini-CEX. Group two (n = 22, Implicit) scored learners at the end of the video solely with the Mini-CEX. For the Explicit group, in the Strong to Weak condition, the FIGR (M = 5.94) was higher than the Mini-CEX Global rating (GR) (M = 3.02, p < 0.001). In the Weak to Strong condition, the FIGR (M = 2.44) was lower than the Mini-CEX GR (M = 3.96 p < 0.001). There was no difference between the FIGR and the Mini-CEX GR in the consistent condition (M = 6.61, M = 6.65 respectively, p = 0.84). There were no statistically significant differences in any of the conditions when comparing both groups' Mini-CEX GR. Therefore, raters adjusted their judgments based on the learners' performances. Furthermore, raters who made their first impressions explicit showed similar rater bias to raters who followed a more naturalistic process.