KS3/4 - How is KS4 Value Added (VA) calculated?

This article provides an in depth look at the DfE's EBacc Value Added measure and how it is calculated. This can help with troubleshooting figures, or for those who are interested in the detail behind the measure calculations.

What is Value Added?

Value Added (VA) is a performance measure that calculates how much progress students have made from the beginning to the end of their secondary education (KS2 to KS4), compared with performance of students with the same KS2 prior attainment achieved nationally. Students require a KS2 APS above 0, and to be entered into each of the EBacc elements to be included.

Analytics calculates Value Added element figures for Science, Humanities, and Languages EBacc in the KS3/4 reports, as these are the only elements the DfE calculate officially (The separate Progress 8 measure is calculated for English and Maths).

What students are included?

As per DfE guidance, a student would require the following to be included in the measure:

• Average KS2 score above 0 to be included
• Entry in the EBacc element corresponding to that VA element (Entry into Science EBacc Element for Science VA, Humanities EBacc Element for Humanities VA, and Language EBacc Element for Language VA)

Calculating KS4 Value Added

The formula to calculate KS4 EBacc Value Added is as follows, however, we have also broken down each step in more detail below:

The whole school value added can then be calculated using the following method:

*The coverage is the number of students with a KS2 APS above zero AND entered for that EBacc element. 

KS4 Value Added - Worked Example

1 / KS2 Prior Attainment

To calculate a student’s VA score in each element, their KS2 prior attainment must be calculated first. This is the average of your students’ official core KS2 levels for that reporting year.

For example, Student A achieved a Scaled Score of 90 in KS2 English Reading and 85 in KS2 Maths. So their KS2 prior attainment would be calculated as follows:

Student A's KS2 = (90 + 85) / 2 = 87.5

2 / Science, Humanities and Language grade points

The next step is to find the points for Science, Humanities, and Languages.

• Humanities and Languages - This would be the points from the student’s highest-scoring EBacc Humanities or Language grade. For example, if a student had a 5 in Geography and a 6 in History, the History grade 6 would count for Humanities.
  
  
• Science - This would use the average points of the 2 grades counting towards the Science element. For example, if a student had a Combined Science grade of 65, then the average points would be 5.5.

For example, Student A has the following grade points for each element:

• Science - 6
• Humanities - 4
• Languages - 4
  
  

3 / Value Added Estimate

The next step is to find the students VA estimates based on their KS2 prior attainment. The following examples are calculated using the 2022 estimates from the DfE.

For example, Student A has a KS2 prior attainment of 87.5. According to the table below, this would give a VA Estimate of 2.39 for Science, 1.99 for Humanities, and 3.53 for Languages:

4 / Value Added Score

Once steps 1-3 have been completed, the student’s Value Added for each element can then be calculated:

5 / Whole School Value Added Score

To calculate whole school VA, sum up your students’ VA scores in each element.

In the example below, this would give a total VA score of 539.14 for Science, 303.54 for Languages, and 460.53 for Humanities. This figure is then divided by the number of students included.

6 / Coverage

The next step is to calculate the number of students included in each VA element (Science, Languages, and Humanities). This is calculated by the number of students with a KS2 APS above zero AND entered for that EBacc element.

For example, there are 208 students in the cohort in total, all of which have a KS2 APS above zero. However, only 120 of these students have an entry in an EBacc eligible Language qualification. Similarly, all students are entered for Science and only 139 for Humanities.

7 / Whole School VA Scores

As mentioned above, the school VA would be calculated by the Total VA Elements Score divided by the Pupils Included (Coverage).

Using this formula, this will calculate the following school Value Added scores:

8 / Confidence Intervals

A Value Added score can be used to calculate a 95% confidence interval, which may be used when the VA score is not fully reflective for a variety of different reasons, for example if a student was absent for their Exam. The confidence interval will provide you with a range of values ensuring that, statistically, you can be 95% confident the schools true VA score lies.

The calculation for confidence intervals is very similar to the Progress 8 confidence interval calculation, however you’d use VA standard deviations, as shown below. This is calculated for each VA Element (Science, Humanities, and Languages) for the school.

The upper/lower confidence limits of this confidence interval is given by the formula:

Where:

This gives the VA upper and lower confidence intervals as follows:

For example, using these formulae, this will calculate the following confidence intervals:

This would then give the following confidence limits:

Thanks for reading!