The awarding body confirmed on Friday (February 28) that a total of 433 exam results from 2013 had been revised upwards following re-marking. The figure comprises 98 GCSE results, 285 AS level and 50 A level results.
A statement from OCR sought to assure “students, teachers and parents that exams being taken this year will not be affected”.
It added: “All schools with students affected have been informed and OCR has reviewed all of its 2013 examinations and uncovered no further problems.”
The mistakes were spotted in the marking of four GCE history and English units, and in the use of an incorrect code on other exam papers.
The OCR statement added: “These were the result of human and process error by a minority of examiners during the transition to online marking. The examiners involved will no longer work for OCR.”
OCR said it has introduced “new and enhanced marker monitoring” for the summer 2014 exams and that “additional analysis will be undertaken at the end of the marking process”.
Responding to the news, the Association of School and College Leaders, said the errors were “extremely serious” but that it was pleased that OCR had strengthened its processes for this year.
However, general secretary Brian Lightman said that the review currently being undertaken by exams watchdog Ofqual into the examination appeals system must be completed as a matter of urgency.
He explained: “It highlights the need to have a rapid, reliable, efficient and fair appeals system, which is at the moment under review by Ofqual. This important review must be completed as a matter of urgency.
“It was very unfortunate that the review was undermined by the unhelpful suggestion that schools were using appeals to ‘game’ the system, when they were in fact acting in the best interests of the young people.”
Mark Dawe, OCR chief executive, said: “On behalf of OCR, I apologise unreservedly to the students, parents and teachers affected. I would like to reassure students taking their exams with OCR this summer that due to the rigorous new measures we now have in place, these issues cannot occur again.
“We have conducted extensive investigations into what went wrong. With the help of our most senior examiners, we reviewed all the relevant papers from last summer’s exams and increased marks on a tiny percentage of papers as a result. Although these changes represent less than 0.03 per cent of the results we issued, we are continually improving our processes to drive down the incidence of marking mistakes.”