Abstract
The outcome of an independent sexology course for Colombian medical students was evaluated by means of the Sex Knowledge and Attitude Test (SKAT), stressing the ‘material’ or ‘substantial: rather than statistical, significance of changes afer instruction. The results indicate that the course was as effective in producing increases in the students’ sexual knowledge as previous non-independent courses, and as effective as them, or more, in modifying positively the students' sexual attitudes. These results are at variance with those of most sex education programmes described so far in the literature, whose effectiveness is in doubt due to the small magnitude of changes after instruction.