There are three types of first-year classes:
• Vocational vmbo: this prepares for the basic vocational and the advanced vocational tracks of vmbo.
• General secondary education (avo): this prepares for the combined track and the theoretical track of vmbo, and for havo and vwo.
• Avo/vmbo (combined): in these classes no differentiation for further education has yet been made.
Pupils who start off in a vocational track in their first year can switch to a higher type (avo) during their school career. Conversely, pupils who start off in an avo class in the first year may move own to a lower type (one of the vocational tracks of vmbo).
This article concerns only pupils who have chosen either one of the vocational tracks or an avo first year. This is because the number of children in combined vmbo/avo classes moving to lower or higher types of education cannot be determined.