Year-on-year changes matter — but cohort size, student mix and exceptional examination years matter too.
Year-on-year comparison is one of the first things most departments do after results day.
It is useful, but it is also one of the easiest forms of results analysis to misread.
Compare the same measures, show cohort size and use percentage-point changes.
Do not assume that a change from one year to the next represents a trend. Look across several cohorts where possible.
For each year show:
This allows you to distinguish between changes in your department and changes seen nationally.
Suppose your grade 7+ rate rises by three percentage points.
If the national grade 7+ rate also rises by three points, your position relative to national may be essentially unchanged.
Conversely, stable departmental results during a national fall could represent an improvement relative to the wider picture.
A movement involving two students can appear dramatic in a small department.
Always ask:
“How many students does this percentage change represent?”
One-year movements are interesting.
Patterns appearing over several years are usually more informative.
For example, repeated evidence of relatively strong top-grade outcomes combined with a larger-than-national group immediately below grade 4 would be worth investigating.
A one-off occurrence may simply reflect the cohort.
Results from 2020 and 2021 were produced under different arrangements because normal examinations did not take place.
2022 was also a transitional grading year as the system moved back towards pre-pandemic standards.
These years should not be treated as ordinary points in a long-term exam-results trend.
It is tempting to see a movement in results and immediately identify an event that “caused” it.
Results analysis cannot usually establish causation that easily.
Use changes to identify areas worth investigating, then test your explanation against scripts, assessments and other evidence.
Use the tutor2u Results Explorer to see how national outcomes for your subject changed over the same period.
For a fuller explanation of exceptional examination years, see How should you compare exam results between years?
Last checked August 2026. This is a plain-English summary of official guidance; always check the linked Ofqual, JCQ and exam-board pages for the definitive rules, which can change.
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