ONE OF last summer's biggest marking blunders has led to 340 GCSE candidates having their exam results upgraded.
All candidates from nine schools had to have their religious studies papers re-marked after the exam board Edexcel discovered "extremely erratic marking" by one examiner.
An investigation found that the experienced examiner had marked the papers with "no rhyme nor reason" despite having graded previous years' papers satisfactorily.
The blunder was picked up after complaints from schools, but the re-mark was extended after the board concluded that all the examiner's marking was unsound.
However, one independent school head has criticised the process after it took five months to get her school's mismarked GCSEs upgraded.
All 47 candidates at St Margaret's school, Exeter, who took the GCSE short course in religious studies were awarded the wrong grade by Edexcel last summer.
Three pupils at the all-girls' school were marked down by three grades, while two who were awarded D grades received As after a re-mark.
Three urther girls who took the full GCSE each gained a grade after their scripts were remarked.
A school spokeswoman said the exam board's error, and the long delay in correcting it, had caused pupils great distress. The mismark had also deterred pupils from continuing with religious studies at A-level, she said.
Headteacher Maureen D'Albertanson said: "The results published in the summer were so startling, with some girls awarded grades of C or even D when all their other results were A and A*, that the school immediately asked for a re-mark.
"These discrepancies have affected the school's position in some league tables and the futures of some candidates in their progress into the sixth form."
A spokeswoman for Edexcel said: "The action taken has ensured that all candidates have now received the results they deserve and that the rigour and robustness of the examining process has been maintained.
"There seems to have been no rhyme nor reason to this mismarking. It was not easy to pick up because there was no pattern to it.
"It was not just a question of this examiner marking too harshly, it was very erratic."
She added that the board would not be using the examiner again.