Results from Ofqual’s national reference test suggested that GCSE grades should drop in English language and be raised in maths this year, but the regulator chose not to act on them, it can be revealed.

The test was introduced by Ofqual in 2017 to provide additional evidence about changes in the performance of 16-year-old students in English language and maths.

This year it suggested that GCSE results should fall in English language at grade C/4 and increase in maths at A/7, compared with 2017. In both cases, the regulator decided not to adjust GCSE grade standards to reflect the findings.

Need to know: Your guide to the test that may decide crucial GCSE grades

Grade boundaries: Using new test to change GCSE pass rate ‘irresponsible’

Related: GCSE results 2019: Four key points

In English, Ofqual acknowledged that seeing a fall in the NRT results was surprising, given the expected “sawtooth effect” of new tests - where results rise in the years immediately after their introduction as teachers become familiar with the demands.

Ofqual chose not to change GCSE grades

However, the regulator chose not to act on the data to adjust GCSE grading, as it did not want to risk “interpreting statistical noise and/or NRT behavioural change as a real change in the anticipated GCSE performance”.

Ofqual also noted, after surveying candidates who had taken the test, that students who had sat the English component of the NRT rated it as less important than GCSEs. So they made less effort, had “lower perceived importance of the NRT, greater indifference to their own NRT performance, less test preparation, less outside-school tuition, and lower views of the utility value and importance of the subject”.

That all led Ofqual to question “whether the changes in NRT results would be reflected GCSE performance”.

And in maths, Ofqual decided not to adjust grades at A/7 as the result was consistent with the “increase that we might expect to see as a result of the sawtooth effect in the first two or three years of a qualification”.

The NRT was introduced to monitor changes in students’ performance after the reform of GCSEs in 2017. This year, just over 13,500 Year 11 students from over 330 schools took the third national reference test in February and March.