After having realised that the short stays of volunteers do not favour the confidence with the students nor the adequate organisation of classes and activities, a long term stay (1 month minimum) is preferable. This requirement is even more logical if the volunteers come to carry out any of the secondary subjects, as to add one of those activities involves a rescheduling of the other classes, a reorganisation in the groups and an additional economical investment to be able to provide the required school material.
Nevertheless, there might be some exceptions and accept shorter stays for any specific reason that the co-founders agree with.
It is important to emphasise that, although the co-founders provide some useful information and as much help as possible about different aspects of the stay, all volunteers are responsible for all their basic needs (journeys, accommodation, food, leisure, etc.), unless agreed otherwise with the co-founders.