Foyle College tells parents that applicants should have 'underlying academic ability'
A grammar school has written to parents discouraging them from seeking places unless their children are "capable" of achieving good GCSE and A-levels.
Foyle College in Derry said parents needed to make sure they applied to the `right' school.
It said prospective pupils needed an "underlying academic ability".
There are concerns that without transfer tests taking place, many schools will be more oversubscribed than usual.
Schools have been told they can use "alternative data as a proxy for academic selection" but the Department of Education has been unable to detail what these might be, or whether they could be considered fair.
Education minister Peter Weir and teaching unions have cautioned against using primary school data.
This includes results from standardised tests, last taken when children were aged nine, or mock transfer papers.
Some children will take the same practice paper up to four times.
Foyle is among a group of schools that awards places based on scores from tests run by the Association for Quality Education.
In a letter to parents, principal Patrick Allen said the school was now devising criteria that would "minimise the number of young people who should be attending Foyle College, having the academic ability, but who will be unable to do so because they don't meet other criteria".
He encouraged parents to consult closely with their children's primary principals as to whether Foyle would meet their needs academically.
"Our expectation is that if your child is awarded a place at Foyle, they should be capable of achieving at least 7 GCSEs at grades A*-B and then go on to study at least 3 A-levels," Mr Allen wrote.
"One of the key determinants of success is how hard your child is prepared to work but an underlying academic ability is also vital so, for example, are they currently achieving at least Level 5 in maths and English?"
The department advises that only a small percentage of P7 pupils should be at Level 5 when leaving primary school - less than five per cent.
In addition, its annual exam data reveals the proportion of pupils who achieve GCSEs at grades A*-C, not A*-B.
Foyle's A-level results have been below the Northern Ireland average for grammar schools for several years.
The most recent statistics show 61 per cent of Foyle pupils achieved three or more A-levels at A*-C, compared to 80 per cent across the north. For 2018, the respective figures were 64 and 78 per cent.
Carla Kieran, founder of the Transfer Test Coronavirus Concern Group, said it had been begging Mr Weir for months to scope out and assess contingencies to testing as it seemed predictable exams would be cancelled.
"In the absence of clear direction on selection criteria, schools like Foyle College are issuing letters and proxy-criteria that has not yet been finalised. It is just adding to the uncertainty and stress to children and families," she said.
"We have not seen any evidence that primary school tests have ever been able to predict GCSE and A-level outcomes. Most parents only enrol their children in transfer tests after deciding if their child will fit into their preferred schools and have taken advice from their primary school teachers already.
"Contrary to Foyle's statement, we think a key determinant for success is the level of teaching, nurturing and pastoral support provided by a school; and that success is not only measured by the achievement of seven GSCEs and three A-levels."
Meanwhile, despite warnings about using primary school data, some grammars have agreed in principle to pursue this.
Primary school data is not listed among the department's recommended admissions criteria.
Dalriada School in Ballymoney wrote to parents saying it would ask for "evidence of academic ability", which would include "recent mock AQE test results, results of any standardised tests and results of any end of year tests in English and maths".
Banbridge Academy also said it wanted to retain some element of academic selection.