An endoscopy simulation system comprising a dummy endoscope (1) having a manually adjustable collar (30). In a real endoscope the collar would be connected to a mechanism for adjusting a stiffness of an insertion portion (3) of the endoscope. A position sensor (38, 39) senses the position of the collar. A controller (26) converts the position of the collar to a value representing the simulated stiffness of the insertion portion for use in the simulation.