When asked if she could guarantee the situation pupils faced last year – when grades were subject to an algorithm and were weighted by a school's past performance or postcode – would not happen again, Shirley-Anne Somerville said: "Absolutely".
Last year, many students had their grades altered by the algorithm after formal exams were scrapped by the Scottish Government amid the coronavirus pandemic.
This year, formal exams have also been suspended, but have been replaced by an ‘alternative assessment’ structure, which has come under fire from students, parents and teaching unions.
Speaking to the BBC, Ms Somerville said: "This year a teacher's judgement is based on an individual's demonstrated attainment. So if your teacher thinks you deserve an A, you will get an A.
"The assessment process is judged by your teacher and they will submit the grade.
"No-one is coming in to overrule that or second guess it. Your teacher will decide your grade, if you don't agree you have direct right of free appeal. No-one is coming in to second guess them or their teacher."
Ms Somerville said she had full confidence in the Scottish Qualifications Authority (SQA), despite last week announcing a reform of the body, as well as Education Scotland.
She told Holyrood the role, remit and purpose of both organisations would be considered, as well as their functions and governance arrangements.
She said: “We do have full confidence in the SQA. But we also know that we need to learn lessons from the experience of Covid and also with the report coming up from the OECD, we, as a government, need to be open to reform, open to challenge and to suggestions of how we should change.
"The qualifications the SQA are delivering this year for young people are sound and they are credible, but that doesn't mean we should stop and we can't and shouldn't look at change and that's what we are determined to deliver."
Teaching unions, however, called for the government to ensure the reforms were more than a “cosmetic exercise”.