Complaints about "bizarre" grades have prompted an investigation by England's qualifications regulator into the quality of GCSE and A-level marking.
The TES can reveal that Eton College is among schools which have contacted the Qualifications and Curriculum Authority (QCA). The independent school has presented the watchdog with a dossier of examples, including two pupils who were given zero marks in a Russian A-level paper, then A grades after re-marking.
The QCA's investigation is looking at whether exam boards could improve the data they use for checking that marking standards have been met. It has reviewed how the awarding bodies handle inquiries about results and appeals.
As the TES was going to press, the QCA revealed its investigation had already yielded one outcome: exam boards are being required to cut the time they take to process enquiries about results from 20 to 18 days in the case of A-levels, where a student's university place is at stake, and from 35 to 30 days in all other cases. The inquiry will not result in retrospective re-grading of last year's papers, but aims to cut mis-grading in future.
The dossier from Eton - the pound;26,490-a-year alma mater of Princes William and Harry - lists complaints about marking in seven GCSE and A-level subjects. The school put in 711 requests for re-marks of last summer's exams. As a result, 11 per cent of those papers were changed, less than 3 per cent of the total papers taken by its pupils.
Eton told the QCA: "That 11 per cent of those we asked to have re-marked had changes in grades seems to us to indicate major deficiencies in board practices."
Latest national figures, for 2006, show that, among more than 7 million A-level papers taken, fewer than 0.1 per cent had grades changed following a re-mark. For GCSEs, the figure was 0.2 per cent.
A senior member of Eton's staff said that if the school's experiences were a guide, the true national figures for wrongly graded scripts could be much higher. The Eton teacher, who asked to remain anonymous, said: "Many state schools have a policy where they do not ask for re-marking because of the cost. We found the inaccuracy of marks right across the examinations and across all boards. A lot of people will be seriously disadvantaged in their careers as a result of unreliable results."
The QCA began its investigation late last year before receiving the Eton dossier but after complaints from some state schools and several leading private schools. In 2006, Haileybury School in Hertford and Epsom College in Surrey had nearly half of their pupils' English GCSEs upgraded after appealing.
Isabel Nisbet, the QCA's director of regulation and standards, has written to union leaders saying she is aware of teachers' concerns. The authority had convened focus groups to examine the issue, she said, and it was commissioning a survey of schools' and colleges' views. It would also be exploring whether exam boards could look at data on pupils' performances across a whole school before issuing results, to help spot odd patterns.
Bad marking, page 4
Leading article, page 28.