Schools have warned of "devastating" consequences after their students' results plummeted in an English language IGCSE taken by almost a third of 16-year-olds in England this year.
Headteachers told TES that they were in a state of "utter shock" at the results, published last week ahead of yesterday's main GCSE results. They fear the outcome could unfairly threaten jobs and lead to forced takeovers of their schools.
In some cases, the proportion of students gaining an A*-to-C grade is almost 20 percentage points below expectations. The falls have prompted calls for an investigation into the results.
This year's grade boundaries on some exam papers were higher than last year's, but Cambridge International Examinations, which runs the qualification, says this was because some of the questions were easier.
Large numbers of state schools switched to what began as an international qualification this summer. The number of entries for the English language IGCSE shot up by two-thirds, from 121,530 in 2014 to 201,858. It retains the coursework and speaking and listening assessments that have been scrapped from the English GCSE.
Bill Watkin, operational director of the Schools, Students and Teachers Network (SSAT), told TES that dozens of academy headteachers had contacted him or used his organisation's forums to raise concerns about this year's results.
"Very experienced and successful schools have been surprised by the changes from what was predicted," he said. "It's clearly a major concern for them, in terms of the effect on young people and on schools' headline figures. It's a source of anxiety, particularly in the high-stakes accountability environment that schools are working in."
Mr Watkin said Cambridge's explanation, that boundaries had been changed to reflect the exam's level of difficulty, "does not match the experiences of headteachers". He called on the exam board to investigate what had happened.
Richard Thomas, executive director of the Association of Secondary Heads in Essex, told TES that several schools had contacted him because they were "alarmed" at their results.
He said he expected between 5 and 10 per cent of the schools that used the IGCSE this year to see a "significant drop" in the proportion of students receiving five GCSEs at grade A* to C including English and maths.
Schools with lower-ability intakes would be the worst affected, he said, because they had more students on the C-D grade borderline. He warned that the apparent raising of the bar this year would cause those students to miss out on the C grade.
School leaders told TES they were concerned about a potential drop in relation to the five GCSE benchmark because it could trigger extra Ofsted inspections, forced academy conversions and job losses for school leaders and teachers (see box, below).
They said they were unaware that Cambridge International Examinations had been following the principle of the controversial "comparable outcomes" system to set grade boundaries for the IGCSE for the past three years, as required by Ofqual.
Roderic Gillespie, assessment director at Cambridge International Examinations, said that grade boundaries were changed in response to the level of difficulty of exam papers.
He added that the C grade boundary had been increased by two marks on this year's IGCSE entry-level reading exam paper and by three marks on the extended reading paper, but had been reduced by five marks on the writing exam because the paper was deemed more difficult.
"The whole premise is to maintain standards year on year," he said, adding that this year's results were relatively stable at a national level, given the huge increase in entries. Results could fall or rise in individual schools in line with changes in cohorts, he said.
An Ofqual spokesman pointed out that the number of candidates taking the qualification had increased by 80 per cent. He said that even if overall ability was comparable to previous years, there could be variations in individual schools.
`The effect could be devastating'
One headteacher, who wishes to remain anonymous to avoid worrying pupils, says that her school had expected at least 78 per cent of students to gain an A*-to-C grade in English language this year, but only 59 per cent did so.
"It's been an utter shock for us," she says. "It looks as if the whole grade system has been depressed.
"The effect on a school could be devastating. This will be bandied around in the local newspapers and people will say we've got a rubbish English department - that's not true."
Another headteacher, who also spoke on condition of anonymity, says: "The whole reason we chose to use the IGCSE was that it was outside comparable outcomes. It was because we thought we'd get more reassurance that grade boundaries wouldn't be affected by government intervention."
She is surprised to learn that the system was in use, and cannot understand what went wrong because Ofsted had this year singled out the English department for praise. "It seems unfair," she says.