ACCUSATIONS that this summer's mathematics Higher has been "dumbed down" by the Scottish Qualifications Authority (SQA) are alarming.

The allegation is made by Clive Chamber, former principal examiner of maths for the SQA between 1992 and 2009, who told The Herald the 2013 paper was easier than any previous exam he had seen.

Having reviewed the paper, as he does every year out of a continuing professional interest in the qualification, the now-retired Mr Chamber said a typical exam should have 35% of questions deemed suitable for "A/B" candidates in order to separate the best-performing pupils from the rest, but he believes only 15% of questions reached the benchmark in 2013.

Mr Chamber also said the paper was "uneven", with harder questions scattered throughout rather than being placed at the end, which he believes makes it more difficult for weaker candidates to finish the paper because they get "stuck".

His views, which were supported by a number of principal teachers, are worrying because maths is the one of the key subjects upon which Scotland's economic future relies and the Higher exam should represent the gold standard within the qualifications system.

One immediate concern is that this was a deliberate move by the SQA to make the examination easier as part of a pursuit of ever-improving standards – which some observers believe has afflicted the exam system in recent years, although nowhere near the same extent as in England. However, although the pass marks for a variety of SQA exams have been creeping upwards in recent years, there is no evidence this was the driving force. Dr Gill Stewart, the SQA's director of qualifications development, has defended the integrity of the exam, insisting it offers an appropriate degree of challenge for candidates at A, B and C level. In her comments to The Herald, she also highlights a range of quality assurance checks which the paper is subjected to prior to being signed off, including vetting and scrutiny by maths practitioners independent of those who set the paper.

Instead, the answer appears to lie in the highly unusual set of circumstances which surrounded this year's exam. Last year, the setting team for the 2012 Higher had a disagreement with SQA officials over the difficulty of the paper and where the pass mark should be set. The principal assessor James Reid subsequently refused to attend a meeting to discuss the disagreement unless a colleague was present and he had his contract terminated. His departure was followed by five other senior examiners, who left in protest at the manner in which he had been treated. After losing his job, Mr Reid warned that the lack of expertise for the 2013 Higher risked damaging the exam. Higher maths is far too important a qualification for there to be any suspicion over its integrity and the SQA must move quickly to ensure there is no repeat of the concerns expressed this year from experts who have taken great pride in the maintenance of standards for nearly two decades.