Trial design
LIVER
We followed the CONSORT statement [We evaluated the effectiveness of 3D PDFs and traditional 2D atlases in teaching two topics: Liver anatomy and male genitalia anatomy. These structures were specifically selected based on their different levels of anatomical complexity, with male genitalia anatomy being considered more complex in comparison to liver anatomy. The complexity was determined based on consensus among the research group that consists of professors, medical educationists, medical doctors, and medical students.The study consisted of two steps. In Step-1, students were randomly assigned to either the intervention group (who watched lecture videos included 3D PDFs) or the control group (who watched lecture videos included 2D atlas images). After the video lectures, a test (the immediate test) was administered to assess their retention performance. In Step-2, the same test (the delayed test) was administered 10 days after the immediate test. Figure 
Trial process