This article provides an in depth look at the DfE's Progress 8 measure, introduced in 2016, and how it is calculated. This can help with troubleshooting figures, or for those who are interested in the detail behind the measure calculations.
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The DfE have stated in their Secondary Accountability Measures guidance: "As primary tests and assessments were cancelled in academic years 2019/20 and 2020/21 due to COVID-19 disruption, there will be no KS2 prior attainment data available to use to calculate Progress 8 when the relevant cohorts reach the end of KS4 in academic years 2024/25 and 2025/26. Having explored alternative options for producing a progress measure in the affected years, we have concluded that there will be no replacement to Progress 8 for 2024/25 and 2025/26" As such, if you wish to calculate Progress 8 figures for the 24/25 (Current Yr 10) and 25/26 (Current Yr 9) cohorts within Analytics, you would need to upload an alternate KS2 Baseline to use in place of these cohorts' Scaled Scores. Some ways schools have done this are outlined the below article: |
- What is Progress 8?
- Calculating Progress 8
- Adjusted Progress 8
- Calculating Whole School Progress 8
- Calculating Confidence Intervals
- Worked Example of Progress 8
What is Progress 8?
Progress 8 compares a student’s Attainment 8 score (explained here) with their estimated Attainment 8 score (which is based on their KS2 prior attainment, and how students within the same KS2 prior attainment group have performed nationally). According to DfE guidance; “A pupil’s Progress 8 score is defined as their Attainment 8 score, minus their Estimated Attainment 8 score”. This figure is then divided by 10 to calculate the average progress per grade.
As this measure uses KS2 data, students with no valid English and Maths KS2 data (i.e. without a KS2 APS above 0) will not have an estimated Attainment 8 score and would therefore be excluded from the Progress 8 measure and the Average Total Estimated Attainment 8 figure.
Calculating Progress 8
The calculation for Progress 8 is as follows:
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Progress 8 (Overall) = |
In addition to the overall Progress 8 score, Analytics also calculates Progress 8 scores for each of the different elements: English, Maths, EBacc, and Open:
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English Progress 8 = (English Score - English Estimate) ÷ 2 |
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Maths Progress 8 = (Maths Score - Maths Estimate) ÷ 2 |
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EBacc Progress 8 = (EBacc Score – EBacc Estimate) ÷ 3 |
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Open Progress 8 = (Open Score – Open Estimate) ÷ 3 |
Adjusted Progress 8
The DfE updated Progress 8 calculations from 2018 onwards to limit the impact of students with a very negative Progress 8 score on the overall school Progress 8 figure. All student Progress 8 scores within Analytics are adjusted based on minimum thresholds provided by the DfE.
As an example, using the 2023 DfE A8 estimates shown below, if a student had a KS2 prior attainment of 103.5, the lowest possible Progress 8 score accepted for them would be -4.136. If their Progress 8 score was calculated below this, it will be adjusted by replacing this with the minimum Progress 8 score for their prior attainment group.
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If a student’s Progress 8 score has been adjusted, an |
Calculating Whole School Progress 8
School Progress 8 can be found by calculating the mean average of a school’s eligible students’ Progress 8 scores.
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School Progress 8 Score = |
*Progress 8 coverage is the count of students included in Progress 8 i.e. those on roll with valid KS2 data in that cohort.
Calculating Confidence Intervals
A 95% confidence interval will also be calculated, defining the range of values within which we are statistically confident that the true value of the Progress 8 score for the school lies. This is calculated for the school’s overall Progress 8 figure, and also each individual Progress 8 element. The confidence interval is given by the formula below:
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Confidence Interval = |
*The Standard Deviation of all Progress 8 and Progress 8 Element scores nationally is provided by the DfE each year.
The upper/lower confidence limits of the confidence interval are given by the formula:
Where:
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Lower Confidence Limit = School Progress 8 Score – Confidence Interval |
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Upper Confidence Limit = School Progress 8 Score + Confidence Interval |
Progress 8 - Worked Example
1 / Attainment 8
To determine a student's Attainment 8, we would need to add up the scores from each of their baskets. For more information on how a student's Attainment 8 is calculated, see our article here - How is Attainment 8 calculated?.
The below student, 'Student A', achieved the following results in 2022:
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Basket 1 (Eng/Mat) |
Basket 2 (EBacc) |
Basket 3 (Open) |
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GCSE Mathematics (3 x 2) |
GCSE History (4) |
BTEC First Award Hospitality (5.5) |
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GCSE English Language (4) |
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BTEC First Award Sport (4) |
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Cambridge National Cert Business & Enterprise (4) |
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Sum Eng and Mat = 10 |
Sum EBacc = 4 |
Sum Open = 13.5 |
Student A's Attainment 8 score would then be calculated as follows:
Student A’s Attainment 8 = (10) + (4) + (13.5) = 27.5
2 / KS2 Prior Attainment
In order to determine a student's Estimated Attainment 8, you would firstly need to calculate their KS2 Prior Attainment.
This is calculated from the average of the core KS2 subjects for that reporting year. For example, for Y11 21/22 and later, this would be the average of the students' English Reading and Maths KS2 Scaled Scores.
Using student A’s KS2 English Reading Scaled Score of 90 and Maths Scaled Score of 85 their average KS2 prior attainment would be calculated as follows:
Student A’s KS2 Prior Attainment = (90 + 85) ÷ 2 = 87.5
3 / Estimated Attainment 8
To determine a student's estimated Attainment 8 score, you can compare the student's average KS2 Prior Attainment with the list of estimates selected by your Sisra Admin when publishing.
Using student A’s prior attainment, we can cross reference this with the DfE’s 2022 validated Attainment 8 estimates to find their estimates for each element in the row for their KS2 prior group:
For example, this would place that student in Prior Attainment Group 3, and their estimates would be 22.75 for the overall, 5.51 for English etc.
You can see a full list of all historical Attainment 8 Estimates in the article linked here.
4 / Progress 8 (Overall)
Using student A’s figures above their overall Progress 8 score would be:
Student A’s Progress 8 Score = (27.5 – 22.75) ÷ 10 = 0.475 (3dp)
This means that this student has achieved roughly, just under half a grade better per subject than other pupils with the same prior attainment nationally.
5 / Progress 8 (Baskets)
Similarly, student A’s individual Progress 8 element scores would be:
Student A’s English Progress 8 Score = (4 – 5.51) ÷ 2 = -0.755 (3dp)
Student A’s Maths Progress 8 Score = (6 – 3.44) ÷ 2 = 1.280 (3dp)
Student A’s EBacc Progress 8 Score = (4 – 6.03) ÷ 3 = -0.677 (3dp)
Student A’s Open Progress 8 Score = (13.5 – 7.77) ÷ 3 = 1.910 (3dp)
6 / Progress 8 (Whole School)
Student A is one of 156 students included in Progress 8 at this school, as they have a KS2 APS above 0. The school Progress 8 score would be calculated as:
School Progress 8 Score = 42.97 ÷ 156 = 0.275 (3dp)
7 / Progress 8 Confidence Intervals
Using the ‘2022' National Standard Deviation and cohort size, the Progress 8 confidence interval would be:
School’s P8 Confidence Interval = 1.96 x (1.408359/√156) = 0.22 (2dp)
Using the School Progress 8 score above, the Progress 8 confidence limits would be:
School’s Lower Confidence Limit = 0.275 – 0.22 = 0.055 (3dp)
School’s Upper Confidence Limit = 0.275 + 0.22 = 0.495 (3dp)
8 / Progress 8 Confidence Intervals (Baskets)
Confidence intervals can be calculated for individual Progress 8 elements in a similar way. For example, if our school English Progress 8 score was -0.561, the English Progress 8 confidence interval would be:
School’s English P8 Confidence Interval = 1.96 x (1.609325/√156) = 0.25(2dp)
Using the School Progress 8 score above, the English Progress 8 confidence limits would be:
School’s English Lower Confidence Limit = -0.561 – 0.25 = -0.811 (3dp)
School’s English Upper Confidence Limit = -0.561 + 0.25 = -0.311 (3dp)
Standard Deviations
These standard deviations are based on the Progress 8 scores of all eligible pupils at mainstream schools and are used within confidence interval calculations.
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Measure |
2016 |
2017 Prov. |
2017 |
2018 Prov. |
2018 |
2019 Prov. |
2019 |
2022 |
2023 Prov. |
2023 |
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Progress 8 |
1.0605 |
1.2394 |
1.229722 |
1.264453 |
1.262617 |
1.282562 |
1.282479 |
1.408359 |
1.412814 |
1.414023 |
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P8 – English Element |
1.1248 |
1.5534 |
1.542787 |
1.512834 |
1.538146 |
1.547167 |
1.546113 |
1.609325 |
1.635252 |
1.635317 |
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P8 – Maths Element |
1.2348 |
1.4051 |
1.397587 |
1.539593 |
1.371335 |
1.365436 |
1.365617 |
1.530366 |
1.488701 |
1.489333 |
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P8 – EBacc Element |
1.3841 |
1.4543 |
1.449435 |
1.371839 |
1.512625 |
1.525590 |
1.526479 |
1.636993 |
1.633377 |
1.635225 |
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P8 – Open Element |
1.2300 |
1.4423 |
1.429360 |
1.483009 |
1.478238 |
1.513246 |
1.511807 |
1.630237 |
1.621232 |
1.623297 |
Thanks for reading!