Subject Value Added and Subject P8 Scores Information (KS4)

Update (Feb 2020) introduces a powerful new tool - 'Subject Value Added' (SVA) - for key stage 4 series.


Based on actual exam results data from all secondary schools across England, 4Matrix have used the National Transition Matrices to calculate the average point score achieved per subject, by key stage 2 prior attainment. This will allow schools to measure past, present and future cohorts against national subject trends per subject, per group, and per pupil, to help determine if they are performing above, on, or below the national standard.


The Calculation differences between SVA and Subject P8


Similar to the existing 4Matrix-devised ‘Subject Progress 8’ scores, our new SVA measure looks at prior attainment compared with a pupil’s outcome to provide a value-added style score. However, SVA does not rely on any Progress 8 parameters and provides a more direct way of comparing your school’s subject performance against the same subject nationally.


  • The Subject VA Score is based on specific grades attained in that subject whereas the Subject P8 Score is derived from the Attainment 8 / Progress 8 measure.
  • For both measures, each pupil will have an estimated grade for each subject based on national data. These are calculated in different ways.
  • The Subject VA estimate is calculated by working out the national Average Point Score attained in each subject.
  • For Subject P8, the estimate is calculated by dividing the national basket (EBacc and Other) score by the national entries in that basket and then giving the same estimate to all subjects that naturally fall in that basket e.g. the EBacc estimate will be the same for all humanity, science and language subjects.


SVA and Subject P8 Score Differences


There are a number of reasons why, for any given subject, the Subject VA and Subject P8 scores can be different.

  • Subject VA is subject-specific whereas Subject P8 is not.
  • Subject P8 is based on Attainment 8 scores. These will be the best 8 grades attained by pupils nationally (with the basket restrictions). This means that pupils lowest value grades are effectively excluded in the national measure. However, all grades are included for Subject P8. Because of this, the Subject P8 pupil estimate will usually be higher than for Subject VA. It follows that Subject P8 scores attained by pupils / subjects will usually be lower than the Subject VA score.
  • The baselines that the measures are based on are different, according to the national data available. Subject P8 uses the P8 Start Point (3.6, 4.2, 5.1 etc) whereas Subject VA uses NC Levels (3a, 4c, 4b etc). 
  • The Subject VA estimate is based on subjects with 9-1 grades only whereas vocational subjects are included in Subject P8.


Interpreting SVA


An SVA score of above 0 signifies that the pupil (class/group/subject) have performed above the national average (leading to positive Value Added). Negative SVA signifies that pupils have performed below the national average (leading to negative Value Added).


For Subject P8 it’s not possible to quantify this. Generally it is more important to look at the ranking of subjects in the same basket.


It must always be noted that currently, national data used in SVA is based on the 2018/19 Y11 results and should be used with caution when applied to previous or current cohorts as it likely to change year-on-year. 


Examples of the calculations are now available in the latest KS4 Guide (available through Help in 4Matrix) and full details, including worked examples, are in the P8 and SVA topics.


We have also published a mini-guide to Subject VA at this link