Every summer, someone points out that a grade 7 needed 62% one year and 58% the next, and asks whether the exam got easier. It is a fair question with a reassuring answer: the boundaries moved precisely so that the grade kept meaning the same thing.
What a boundary actually is
A grade boundary is not a standard set in advance. It is set after the papers are marked, once examiners can see how the cohort performed on that specific paper.
The purpose is comparability. A grade 7 should represent the same level of achievement whether your child sat the paper this year or three years ago. Since no two papers are exactly equal in difficulty, the mark required has to move to keep the grade fixed.
So a lower boundary does not mean a easier exam or a weaker year. Usually it means the opposite: the paper was harder than intended, and the boundary dropped to compensate.
Why they move
Three things drive the shift:
- Paper difficulty. The main factor. A paper with an unusually demanding question set produces lower raw marks across the board, so boundaries fall.
- Cohort performance. Awarding bodies compare this year's cohort with previous ones using prior attainment data, so a stronger or weaker year group is accounted for rather than rewarded or punished.
- Tier and component. Boundaries are set per paper and per tier. Foundation and Higher in the same subject move independently.
How to read a mock result
This is where boundaries matter most for parents, and where they are most often misread.
Schools usually mark mocks against a previous year's boundaries, because this year's do not exist yet. That makes a mock grade an estimate built on a different paper's standard — useful, but not a prediction.
Two practical consequences:
Look at the mark, not just the grade. "58, which was a 6 last summer" tells you far more than "a 6". If the boundary for a 7 was 62, your child is four marks away, and four marks is a conversation about where those marks were lost.
Ask which paper the marks came from. A student can be comfortably above the boundary on Paper 1 and well below on Paper 2, and the averaged grade hides exactly the information that would help.
What this means for revision
Because boundaries respond to difficulty, chasing a percentage is less useful than chasing specific marks. Ask the school — or a tutor — which questions the marks were lost on and why: unfinished, misread, method missing, or genuinely not known. Those four causes need four different responses, and only one of them is about learning more content.