Asked by if she could guarantee that there would not be a repeat of the Scottish Qualifications Authority (SQA) debacle of 2020 – when grades were initially subject to an algorithm until rapidly escalating protests after results day in August ultimately led to a U-turn – she said: "Absolutely".
Ms Somerville also said she retained full confidence in the SQA.
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In an interview broadcast tonight, the education secretary told the BBC: "It's very important that, this year, a teacher's judgement is based on an individual's demonstrated attainment – that's the grade you'll get. So if your teacher thinks you deserve an A, you will get an A from this.
"The assessment process is judged by your teacher and they will submit the grade. No one's coming in then to overrule, to second-guess it, to look at any other material around that. Your teacher will decide your grade [and] if you don't agree with that you have...the direct right of free appeal.
"But [students] should be reassured that no one's coming in to second-guess their teacher or them during this process."
Some teachers have pointed out, however, that grades submitted by schools could be partly determined by past attainment levels in each school, and that in this regard the approach would not be entirely different to that used in 2020, before the Scottish government's U-turn.
In an address to the Scottish Parliament last week, Ms Somerville gave long overdue details of this year's SQA appeals process and, controversially, revealed that it could lead to grades going up or down.
The next day, first minister Nicola Sturgeon insisted that she still had full confidence in the SQA, around two hours before Ms Somerville announced that both the SQA and Education Scotland were to be reformed.