The Power of One Word to Paint a Halo or a Horn: Demonstrating the Halo Effect in Learner Handover and Subsequent Evaluation

PURPOSE: Learner evaluation based upon direct observation is a cornerstone of modern competency-based medical education. Learner handover has become a widely accepted practice. Cognitive attribution bias is a potential threat to the validity of learner evaluation following learner handover.

METHOD: In this 2 x 2 (learner handover: halos/horns x learner gender: man/woman) factorial, nonequivalent comparison group experimental design, registered attendees at a national medical education conference watched 1 of 2 videos (depicting a woman learner or man learner) of simulated learner-patient encounters. Data were collected on April 30 and May 1, 2022. Participants received learner handover conditioning prior to watching the video. The conditioning was randomized to suggest the learner they were about to watch was either "above-average" (halos) or "below-average" (horns). Following the video, participants completed an evaluation form.

RESULTS: Participants rated the learner in a video encounter preceded by a horns statement significantly lower than the learner in a video encounter preceded by a halo statement, F (1,65) = 10.15, P < .01, η2 = .14, (horns meanadj = 12.49 (CI 11.34, 13.63), halo meanadj = 15.10 (CI 13.93, 16.28). This represented a scoring difference of 2.61 points on a 30-point scale. More years of teaching experience was negatively associated with the score, F (1,65) = 13.44, P < .001, η2 = .17.

CONCLUSIONS: Learner conditioning differing by a single word, labeling a learner as either "above-average" or "below-average" resulted in a large difference in scoring by medical educators.