Endoscopic endonasal surgery requires many skills: a learning program was developed with progressive steps, on a surgical simulator (Cyrano) designed to train junior surgeons in the acquisition of basic endoscopic surgery skills and to assess their progress. The main objective of this study was to establish the construct validity of these exercises and to refine objective criteria to establish students’ level.

Thirty volunteers with varying experience in endoscopic endonasal surgery were blindly evaluated on 4 modules according to objective and subjective criteria.

Ten beginner, 11 intermediate and 9 expert level participants were included. For each exercise, at least one criterion was discriminant for level of expertise. Weighted scores succeeded in discriminating groups. Interpretation of a single criterion must remain cautious and evaluation should rather rely on composite scores, which better reflect the participants’ level. Useful criteria and their reference values are specific of each exercise. Face and content validity were rated at 3.92/5 and 4.59/5 respectively (5-level Likert scale).

The construct/face/content validity of the proposed modules have been verified. Most of the modules tested here were physically not realistic, but they were all rated as highly relevant for surgical training by the participants.