Sonar TrackerSisra Multi-School
How trust figures are calculated
Sisra Multi-School does not recalculate anyone’s results. Each school’s Sisra Analytics works out every pupil’s and student’s measures when it publishes, and Multi-School adds them up across the trust. By default it treats the trust as one large school, which is not how the DfE builds its trust measures.
Where the numbers are made
Section titled “Where the numbers are made”When a school publishes grades, its Sisra works out each pupil’s or student’s measures, such as Attainment 8 or a value added score. It uses the options the school chose: the DfE rules year, the estimates and the Data Collaboration year. If the publish passes Multi-School’s checks, Sisra sends the results on.
Multi-School keeps each school’s latest publish for each cohort, term and grade type. Together these make a data collection, such as Year 11 Term 1 - Predicted. When a school publishes again with the same term and grade type, the new publish replaces the old one.
So a trust figure combines every school’s latest publish, each made with that school’s own choices. Get school data into Multi-School explains the checks.
The trust as one school
Section titled “The trust as one school”By default, each trust figure is worked out across all the trust’s pupils or students, as if the trust were one large school. It is not the average of the schools’ own figures, so large schools count for more than small ones.
Worked example: grade 5 or above in English and maths
Section titled “Worked example: grade 5 or above in English and maths”A trust has three schools with pupils in year 11.
| School | Pupils | Grade 5 or above in English and maths | School figure |
|---|---|---|---|
| School A | 180 | 99 | 55.0% |
| School B | 120 | 48 | 40.0% |
| School C | 60 | 12 | 20.0% |
| Trust | 360 | 159 | 44.2% |
Multi-School shows 159 ÷ 360 = 44.2% for the trust. The average of the three school figures would be 38.3%. The difference comes from School A, which is the largest school and has the highest figure.
KS5 works the same way
Section titled “KS5 works the same way”At KS5, every entry across the trust counts, weighted by the size of its qualification. Suppose School A has 60 A level entries with an average value added of +0.20, and School B has 20 entries averaging -0.40. Each A level has a size of 1.
The trust’s value added is (60 × 0.20 + 20 × -0.40) ÷ 80 = 4 ÷ 80 = 0.05. The average of the two schools’ figures would be -0.10.
KS5 figures have no weighting option. Juniper’s product documentation says they include every school that publishes, however recently it joined the trust. This guide could not check it in the product.
DfE weighting at KS4
Section titled “DfE weighting at KS4”The DfE publishes its own KS4 measures for trusts. It weights each school by its size and by how long it has been in the trust. Apply DfE Weighting weights Multi-School’s KS4 figures in the same way.
How the DfE weights schools
Section titled “How the DfE weights schools”As at its 2025 guidance (updated 16 October 2025), the DfE’s KS4 trust measures work like this:
- they cover state-funded mainstream schools only, so special schools, pupil referral units and alternative provision are left out
- a trust gets measures only when at least three schools with KS4 results have been in it for at least three academic years
- schools in the trust for fewer than three years are left out, so some trusts’ measures cover only some of their schools
- each school is weighted by its pupils at the end of KS4 and by its years in the trust, with five or more years counting as 5
The guidance names the two factors. The DfE’s methodology multiplies them: in its 2017 to 2018 worked example, a school with 30 pupils and 5 years has a weight of 150.
For the 2024 to 2025 measures, a school counted only if it joined the trust before 12 September 2022. Those measures were due in February 2026, from the DfE’s revised data. The method is in the DfE’s secondary accountability guidance on GOV.UK.
What Apply DfE Weighting does
Section titled “What Apply DfE Weighting does”Apply DfE Weighting is not ticked when a report opens. It is on the Overview and on the Attainment 8 & Progress 8, Basics and EBacc (English Baccalaureate) reports. Subject reports and KS5 reports do not offer it.
Multi-School counts each school’s years in the trust at the point the cohort gets its exam results, from Settings > School Joining Dates. The weight stays the same for that cohort throughout KS4. The dates on grades uploaded to Sisra are not used.
Weighted figures appear only where at least three schools with KS4 results have been in the trust for at least three academic years. With weighting on, the Schools Overview tables show each school’s weighting. Check the joining dates before you rely on a weighted figure.
Juniper’s help articles do not say whether weighted figures leave out schools in the trust for fewer than three years, as the DfE’s do. This guide could not check it in the product.
Worked example: Attainment 8 with and without weighting
Section titled “Worked example: Attainment 8 with and without weighting”The same three schools have these Attainment 8 results.
| School | Average Attainment 8 | Pupils at the end of KS4 | Years in the trust | Year weight | School’s weight |
|---|---|---|---|---|---|
| School A | 48.0 | 180 | 6 | 5 | 900 |
| School B | 42.0 | 120 | 4 | 4 | 480 |
| School C | 39.0 | 60 | 3 | 3 | 180 |
| Method | Calculation | Trust Attainment 8 |
|---|---|---|
| Apply DfE Weighting ticked | (48.0 × 900 + 42.0 × 480 + 39.0 × 180) ÷ 1,560 | 70,380 ÷ 1,560 = 45.1 |
| The trust as one school, the default | (48.0 × 180 + 42.0 × 120 + 39.0 × 60) ÷ 360 | 16,020 ÷ 360 = 44.5 |
| The plain average of the three schools | (48.0 + 42.0 + 39.0) ÷ 3 | 43.0 |
School A counts most under weighting, because it is the largest school and has been in the trust the longest.
Where estimates and benchmarks come from
Section titled “Where estimates and benchmarks come from”Each school chooses its estimates and comparison data when it publishes. Multi-School uses whatever each school chose.
| Figure | Comes from | Where the school chooses it |
|---|---|---|
| Progress 8 (KS4) | The Attainment 8 estimates the school published with: the DfE’s, Sisra Data Collaboration’s or its own | A8 Estimates: in the publish dialog |
| Subject Progress Index (SPI) (KS4) | The Data Collaboration year the school published with | Collaboration Data: in the publish dialog |
| The benchmark (KS4) | The same Data Collaboration year: the average of the schools that took part that year | Collaboration Data: in the publish dialog |
| Value added (KS5) | The DfE national data year chosen for the cohort | Using data from on the KS5 Value Added page |
Juniper Education advises the same estimates for every school and every report in a cohort. As at 12 October 2026, that means the 2024 official Attainment 8 (A8) and value added (VA) estimates and 2024 Collab for the 26/27 cohort onwards. To change a choice, the school’s Sisra administrator republishes. To see what each school chose, see Check the options each school published with.
The benchmark comes from the schools that opted in to that year’s Sisra Data Collaboration. It is not a DfE national figure. For a current cohort it usually comes from an earlier year’s exam results.
Why trust figures can differ from the DfE’s
Section titled “Why trust figures can differ from the DfE’s”| Point | Multi-School | DfE trust measures |
|---|---|---|
| Method | The trust as one school, unless you tick Apply DfE Weighting | At KS4, each school weighted by its pupils and its years in the trust. At 16 to 18, by its pupils only |
| Schools | Every school that publishes for the trust | Mainstream schools in the trust for at least three academic years |
| Pupils | The pupils on roll in each school’s student data | The DfE’s KS4 pupil list, which schools check in the June checking exercise |
| Results | What each school published, often results-day grades | Revised data, with late results and re-marks |
| Rules and estimates | The DfE rules year and estimates each school chose | The DfE’s own rules and averages for that year |
| Progress 8 for 2025 and 2026 leavers | Only from schools’ unofficial KS2 conversions | Not published, because these pupils took no KS2 tests |
| Timing | Whenever schools publish | Months later: February 2026 for the 2024 to 2025 measures |
At KS5, Multi-School has no weighting and, as documented, includes every school, whatever its joining date. The DfE’s trust measures methodology (March 2023) applies the three-year rule at 16 to 18 too. To compare with a DfE trust figure, filter out schools that have been in the trust for fewer than three academic years. Progress 8 for cohorts without KS2 results explains the 2025 and 2026 gap.
What the figures do not tell you
Section titled “What the figures do not tell you”A trust figure is an average across schools of different sizes. A small school can barely move the trust figure but swing a long way on its own. Read the number of pupils or students before any percentage.
A difference between two schools is a reason to ask questions, not a verdict on either school. Check first that both published with the same estimates and comparable data.
Each figure is only as good as each school’s set-up. A missing QN (qualification number), an unmapped key filter or an old publish in one school changes the trust’s figure.