Researchers at Hamburg university have found a big discrepancy between children’s school marks and their performance in tests for the Expansion of the Progress in International Reading Literacy Study.

In Germany, teachers’ recommendations determine whether a child will attend a hauptschule (for lower-achieving 11 to 16-year-olds), realschule (for average achievers who can go on to sixth form at grammar school) or gymnasium (grammar school). A child’s fate is decided after four years of primary school. Experts concluded that too many children were recommended for the wrong school at a critically early stage.

The researchers tested 10-year-olds in maths, science and reading in six of the 16 regional states.

The discrepancy between a child’s test results and his or her school marks is due to the absence of uniform guidelines. Teachers tend to compare children’s performance with their classmates and award marks accordingly.

The researchers also concluded that social background played too big a role in deciding a child’s secondary school and that children’s abilities were not taken into sufficient consideration. In prosperous Baden-Wuerttemberg state, for example, the child of professional parents is nearly four times as likely to be recommended for grammar school as his working-class peer - even if both have the same marks.

In all the states, children from migrant families who had done well at primary school were less likely to be recommended for grammar than a German child with a mediocre record.

Edelgard Bulmahn, the federal education minister, called this an “alarming state of affairs” while Eva-Maria Stange, chairwoman of Germany’s biggest teachers’ union, described the end of primary school as “a farce”.

A national study last year confirmed that many 15-year-olds were in the wrong schools. The Hamburg researchers recommended that pupils be allowed to transfer between secondaries at a later stage.