The Dutch educational system divides children in educational levels around the age of 12. In the last year of primary school, a test called the "Cito Eindtoets Basisonderwijs" is taken to help choose the appropriate level of secondary education/school type. Although the ensuing recommendation is not binding, it does have great influence on the decision making process. Unless caretakers identify the need, in most cases an IQ test is not given to a child, which may result in some children who for various secondary reasons do not function well at school, but who do have the academic ability to learn at the higher levels, mistakenly being sent to the lower levels of education. Within a few years these children can fall far behind in development compared to their peers who were sent to the higher levels.
It is possible for students to move up (or down) from one level to another level. If there is doubt early on about the level chosen, an orientation year may be offered. However, moving up a level later on may require a lot of extra effort, motivation and time resulting in some students not reaching their full potential.
Research has shown that 30% of gifted children are (mistakenly) advised to attend the VMBO, the lower level to which 60% of twelve-year-olds are initially sent. In this particular group of children there is a higher than normal percentage of drop-outs (leaving school without any diploma).
Although IQ testing may aid to reduce mistakes in choosing levels, research has also shown that IQ is not fixed at the age of 12 and may still improve with exposure to the proper educational stimuli, which the current Dutch system by design (early separation into levels) may fail to provide.
Another area of concern is that although parents have the right to have their voice heard in the school's decision making process, not all parents make use of this right equally, resulting in unequal opportunities for children.
In spite of the above disadvantages/risks associated with the long-standing Dutch policy of early separation into levels, the Dutch secondary education system produces very good results and is ranked high compared to that of other countries.