Colin Dexter, author of the Inspector Morse murder mysteries, built the plot of one of his early novels around a particularly subtle murder, involving cyanide, at an Oxford examinations syndicate. Sometimes working for England’s major exam boards must seem like murder too.

The complexities of setting exams, marking and moderating them each year to ensure consistency of standards over time, and taking into account periodic changes of system, is enough to drive ordinary folk to distraction. Thank goodness we have experts who thrive on making these difficult judgments. It is because of them that confidence in the quality of public exams is high. We need to keep it so.

That is why the report by Warwick Mansell, our assessment specialist, that the largest exam board AQA has been prevailed upon to lower the marks needed for a grade C in the new science GCSE, to bring it into line with the the other two boards, is of particular concern (see page 8).

In itself, the decision cannot be described as a deliberate attempt to lower standards compared with previous years. But it is controversial for two reasons.

The first is that it was reached, with reluctance, after a request by the Government’s fledgling qualifications regulator, Ofqual, which wanted to bring AQA’s grade boundary into line with those set by Edexcel and the OCR. The request by Ofqual could easily be interpreted, at best, as a weak response and, at worst, as a green light for a lowering of standards.

The second is that it risks undermining support for the new science GCSE. This qualification, along with the new additional science exam, is designed to increase pupils’ engagement in the subject by introducing topical issues such as genetic engineering and global warming.

If Ofqual is to become an effective and truly independent watchdog it needs to be given the power to direct the exam boards when necessary to set appropriate grade boundaries in exams to ensure that standards are maintained. Currently, it has no such power. This glaring omission should be rectified when the legislation to establish the regulator goes through Parliament next year. Such action is vital if teachers, parents and pupils are to continue to have confidence in our exam system.