| Variable | Median | Mean | SD |
|---|---|---|---|
| Age, years | 24 | 25.1 | 4.6 |
| Computer experience, scale (1-7 low to high) | 4 | 4.1 | 2.1 |
| Visual-spatial ability, MRT-A test (0-24) | 8 | 7.9 | 2.4 |
| Introductory interest in surgery (1-4, low to high) | 4.3 | 3.9 | 0.8 |
| Introductory intrinsic motivation (1-7, low to high) | 5.3 | 5.2 | 0.7 |
| Introductory self-determination index (-18 - +18, low to high) | 10.9 | 10.8 | 2.4 |