One in 10 children in state primary schools in Kent fails the 11-plus exam but achieves high key stage two scores, according to a new study.

Analysis, carried out by Education Datalab, found that 10 per cent of children in the selective county don’t do well enough to get into a grammar school - but do well in their Sats (scoring 330 or more overall at KS2).

Meanwhile, one in 10 children in state primary schools passes the 11-plus exam but scores below average in their key stage two exams - taken eight months later.

Rebecca Allen, director of Education Datalab, told headteachers of secondary modern schools today: “This is reminding me that the 11-plus is an incredibly unreliable test.”

Speaking at the National Association of Secondary Moderns (NASM) annual conference, Dr Allen added that not enough people realise that non-selective schools have a number of children with high KS2 scores - a level 5 under the old system. 

High attainers ‘bring down Progress 8 scores’

And often it is high attainers who bring down a secondary modern school’s score under the government’s new Progress 8 performance measure, Dr Allen added.

She said: “As a sector that is what your data is typically looking like. It clearly presents a bit of a problem because you are risking hitting whatever accountability metrics [define] coasting schools or even floor standards problems.”

Dr Allen added that these schools also have a harder job in explaining to Ofsted inspectors that there’s a reason for the problem.

She said: “You can’t go to Ofsted and say, ‘You have got to ignore the data on high attainers.’ But I think the work I have done looking at the Kent data has made me really think hard about the challenge that you have. 

“You have got all these high attainers in secondary moderns, and policy narrative is framed around this idea that these students don’t exist and they do. And unless we improve the 11-plus considerably, there is going to be high misclassification of students.”

A full analysis of the data from Kent, supplied under the Freedom of Information Act, is due to be published next week.

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