Statistical analysis
Statistical analyses were carried out using SPSS v22.0 for Windows. A In order to ensure that randomization worked well, the group characteristics in terms of gender, year, and repeating Year-2 were compared between the intervention group and the control group by using Chi-squared test.The Step-1 liver anatomy and male genitalia anatomy (immediate test) scores were compared between the groups to evaluate the difference in short-term retention. Since the data violated normality assumptions, Mann-Whitney U test was performed to investigate whether there was a significant difference in retention performance between the two groups.The same comparison was carried out in Step-2 (delayed test) for evaluating long-term retention. For the validity of the analysis, participants who were repeating Year-2 were excluded from the Step-2 analysis because they were not re-randomized into the groups. Due to the violation of normality assumptions, Mann-Whitney U test were performed to compare the scores of the two groups.Based on the fact that our participants comprised of Year-1 and Year-2 medical students, we conducted subgroup analyses (Mann-Whitney U test) both in the immediate test and the delayed test scores.To evaluate the reliability of the tests, Cronbach’s alpha values were calculated. The acceptable level of Cronbach’s alpha values was determined as 0.70 [Effect sizes were calculated using Cohen’s d, and were interpreted as small, medium, and large for values of 0.2, 0.5, and 0.8, respectively [