Ratings for each item in the category ‘Visualisation’. The ratings are presented as the mean ± standard deviation. For the first lecture series, the ratings of the lecturers without didactic training are shown in light grey, and the ratings of the lecturers with didactic training are shown in dark grey. The corresponding results for the second lecture series are shown directly above in the white boxes. Significance of improvement after intervention: *p < 0.005; °p < 0.05; and n.s. = not significant.