Ofqual has warned schools of the importance of entering pupils for the correct GCSE paper for their ability after thousands ended up with no grade last year because they were in the wrong tier.
In summer 2019, just under 4,500 pupils received a U in combined sciences after being entered for the higher tier paper, for which the minimum standard is supposed to be equivalent to a grade 4.
"We have again written to headteachers of all schools and colleges in England to remind them of the advice we’ve previously given about choosing the appropriate tier of entry, because the consequences of getting it wrong can be detrimental to students," Ofqual's standards director Cath Jadhav writes in a blog published today.
"This is particularly important for students being entered for the higher tier, where grade 4 (4-4 in combined science) is the lowest available grade.
Ofqual: Warning over GCSE combined sciences
"In 2019, just under 4,500 students were ungraded on higher tier combined science, out of a total entry of over 140,000. This is significantly less than the 11,000 students that would have been ungraded in summer 2018 if no action had been taken, but still a relatively high number."
In 2018, Ofqual introduced a grade of "3-3" for higher tier in the double award combined science GCSE to ensure that students who should have been entered for foundation tier would not get U grades.
However, last year the watchdog reduced the width of this "safety net", with a minimum 4-3 grade for higher tier candidates. And if they missed this standard, they did not achieve a grade at all.
GCSEs in maths, statistics, the sciences and modern foreign languages are all tiered.
Ms Jadhav said that students who are expected to achieve grade 4 or 5 should be entered for the foundation tier, and noted that some "membership organisations" had previously given schools the opposite advice, with recommendations that borderline pupils be entered for higher tier.
She has reminded schools that exam certificates do not specify whether pupils have taken foundation or higher tier, and that it was no easier to achieve a grade 4 or 5 in one tier than another.
Ofqual has also issued a warning over language GCSEs. "Heads of modern foreign languages will be aware of our recent announcement that we will make a small adjustment to GCSE French and GCSE German in 2020, to align the standards with those in GCSE Spanish," Ms Jadhav said.
"This will be a small adjustment at grade 4, so we strongly suggest it should not influence tier entry decisions for 2020."