Impact of the supervisor
Of the 315 randomized students, 302 completed the trial. Of these, 150 students were exposed to a supervisor who did not oppose the DRP, and 152 students were in the control group. The supervisor did not have an impact on the preference score between DRPs and no DPRs. The mean (SD) score for vignettes with versus without exposure to the supervisor was − 0.95 (3.54) versus − 1.7 (3.39) (mean difference [95% CI] 0.79 [− 0.38; 1.94], p = 0.16) (Figs. Impact of the exposure to a supervisor who does not object DRP on PhD student’s research practices.