Prof Scott, of Dundee University, acknowledged the Scottish Government and its education agencies faced “intolerable time pressure and a unique set of circumstances, often beyond their control.”
However, he said the pupils who sat the qualifications were the “greatest losers” as they “now face the situation that their qualifications may be inaccurate, perhaps significantly so in some subjects.”
While the majority of pupils who entered work, college or university last year based their applications on qualifications obtained before the pandemic, Prof Scott said that would not be the case this year and the assessment system “must improve.”
Around 124,000 qualifications were initially downgraded under a moderation process that took into account a school’s historical results, which led to pupils from the poorest areas being twice as likely as those from the richest to have their grades lowered.
Nicola Sturgeon argued that the process was necessary to prevent results being vastly inflated and the qualifications’ credibility being undermined.
However, John Swinney, her Education Secretary, then performed a spectacular about-turn and dropped the Scottish Qualifications Authority (SQA) algorithm, meaning results were based on teacher assessments alone.
Mr Swinney has cancelled this year’s exams and grades will be awarded based on coursework throughout the school year and teacher judgement. No algorithm to moderate the assessments will be used.
It has previously emerged that the overall Higher pass rate increased by 14.4 points to 89.2 per cent per cent last year, while the figure for Advanced Highers rose by 13.7 points to 93.1 per cent
But Prof Scott analysed the results for each subject for the first time in the paper, titled An Impossible Situation, which was yesterday sent to Holyrood’s political parties.
His analysis found that 29 Higher subjects “including almost all of the main academic subjects which form the building blocks of progression to college or university” saw an increase in their pass rate between three and 13 times higher than previously.
A further nine subjects saw their pass rates increase at double the highest rate previously found. For chemistry, the increase was 11 times the previous highest rise and for physics seven times.
Although not as extreme, among the other subjects to show “significant patterns of pass rate inflation” were history, geography, French, Spanish and computing science.
Prof Scott highlighted a range of mistakes that made the “perilous situation” worse, including “variable” methods of grade estimation used across the country and “variable local quality assurance.”
However, he also highlighted a “few key instances of inappropriate political decision-making” and argued Mr Swinney precipitated an “unnecessary second crisis” by reverting to teacher judgements after dumping the algorithm.
Instead he argued “an accurate evaluation of the extent to which all learners had been under or over-valued by the inaccurate estimation and moderation process was urgently required.”
Jamie Greene, the Scottish Tories’ Shadow Education Secretary, said: “Jim Scott’s report must be an urgent wake-up call for SNP Ministers to guarantee that this year’s cohort of pupils will not end up in a similar chaotic situation.
“A repeat of last year’s shambles would be unforgivable and one which Scotland’s students would not easily forgive or forget.”
A Scottish Government spokesman said: “The Deputy First Minister made clear that lessons had to be learned from last year’s qualifications process, which is why swift action was taken to commission Professor Mark Priestley to carry out an independent review.
“Decisions on how 2021 National Qualifications are awarded have been informed by Professor Priestley’s recommendations, along with close collaboration and consultation with education experts, pupils, parents and other stakeholders.
“This year’s results will be based on teacher judgement of evidence of pupil attainment, with local and national quality assurance processes to ensure consistency and accuracy in applying national standards.”
— to www.telegraph.co.uk