- Introduction
- About these tables
- Key Stage 2 to 3 CVA measure
- Key Stage 3 Test results
- More information
- About these tables
- Abbreviations and their meanings
- Ordering further copies
- Copyright
- Guide to CVA
- Ready Reckoner - Key Stage 2 to 3 Special schools
- Ready Reckoner - Key Stage 2 to 3 Mainstream schools
- Point scores for tests and examinations
Department for children, schools and families
Achievement and attainment tables
Secondary Schools (KS3) Achievement and Attainment Tables 2007
Following a successful pilot in 2006, based on established KS2 to 4 CVA methodology, we are publishing for the first time this year a KS2 to 3 CVA measure for all maintained secondary schools.
More information on the CVA pilots can be found on our website at www.dcsf.gov.uk/performancetables.
What is CVA?
Some pupils will find it particularly difficult to reach the level expected for their age in assessment tests. It may be, for example, that they have significant special educational needs (SEN). But all pupils are capable of making progress and it is important that schools are given recognition for the work that they do with all their pupils.
We measure the progress that individual pupils have made between tests when they are in Year 6 (KS2), generally aged eleven, and tests taken when they are in Year 9 (KS3) and generally aged 14.
When comparing the performance of schools it is important to recognise the progress they have helped pupils make. Measures of absolute attainment therefore need to be complemented by measures of the progress made by pupils - the value added - from one key stage to another.
Value Added (VA), which was first published in the Secondary School (KS3) Performance Tables in 2003, did this by comparing the results achieved in Year 9 against a pupil's starting point (or prior attainment) - the results of KS2 assessments in Year 6.
CVA is not very different from VA. The basic principle of measuring progress from the KS2 to 3 remains the same. However, a number of other factors which are outside a school's control, such as gender, special educational needs, movement between schools, and family circumstances, are also known to affect pupils' performance.
CVA therefore goes a step further than VA by taking these factors into account and thus gives a much fairer measure of the effectiveness of a school. That means that comparisons against other schools are more meaningful, such as, for example, when comparing the performance of a school in a rural area against the performance of one in an inner city area - both of which might face quite different challenges.
This means that CVA gives a much fairer statistical measure of the effectiveness of a school and provides a solid basis for comparisons. Nevertheless, no single measure of performance can tell the whole story about a school's effectiveness and CVA must not be viewed in isolation. Attainment data continues to play an important role in painting the full picture of a school's performance.
Calculating the CVA scores
We base each pupil's CVA score on a comparison between their actual KS3 performance and the KS3 performance predicted for each pupil by the CVA model, having taken into account the range of factors affecting performance.
An average of all pupils' CVA scores is produced for a school. That average is adjusted by the CVA model to account for cohort size, which then produces a school level CVA measure. This number is presented as a number based around 100. This indicates the value the school has added on average for its pupils.
Coverage of CVA
CVA covers all maintained schools and non-maintained special schools. CVA models have been produced separately for mainstream schools and special schools.
Interpretation of a school's CVA score
The CVA section shows, for each school:
- the KS2 to 3 CVA score
- the upper and lower limits of a 95% confidence interval
- a coverage indicator.
The coverage indicator shows the percentage of pupils at the end of KS3 included in the CVA calculation. This might not be 100 per cent because we do not have the KS2 test results for some pupils - for example, because they were previously educated outside England. If the coverage is very low (below 50 per cent) then the CVA score is not published because it does not properly represent the effectiveness of the school.
The CVA measure is shown as a score based around 100. Scores above 100 represent schools where pupils on average made more progress than similar pupils nationally, while scores below 100 represent schools where pupils made less progress.
What a school's CVA measure tells you
For KS2 to 3 CVA, a measure of 101 means that, on average, the school's KS3 cohort has achieved one term's more progress than the national average. A score of 99 means that the school's pupils made a term's less progress.
The CVA measures give the best indication in these tables of school's overall effectiveness. But the significance that can be attached to any particular school's CVA measure depends, among other things, on the number of pupils included in the CVA calculation.
The smaller the number of pupils, the less confidence can be placed on the CVA measure as an indicator of whether the effectiveness of a school is significantly above or below average.
Confidence intervals
The CVA measure is a statistical means of assessing the relative effectiveness of school or pupil progress between KS2 and KS3.
CVA is, however, based on a given set of pupils' results for a particular test paper on a particular day. A school could have been equally effective and yet the same set of pupils might have achieved different results on the day. And the school would almost certainly have shown slightly different results with a different set of pupils, even with the same levels of prior attainment.
Hence, although the CVA is based on all pupils in the school cohort, not just a sample of them, this degree of uncertainty should be taken into account if interpreting the figures as estimates of a school's effectiveness.
The uncertainty of a CVA score as a measure of school effectiveness can be presented as a confidence interval (CI). This is a range of scores within which we can be statistically confident that the 'true' school effectiveness will lie.
The degree of significance that can be attached to a school's CVA measure depends, among other things, on the number of pupils included in the calculation.
The CVA methodology produces a 95 per cent CI to show the range within which we can be confident the CVA measure represents the overall effectiveness of a school.
If a school cohort is large the width of the CI will be small, but if a school cohort is small the CI will be wide.
A school level CVA measure must always be interpreted alongside the CI. Schools where the lower limit of the CI is above 100 represent schools where pupils on average made significantly more progress than pupils nationally, while schools where the upper limit of the CI is below 100 represent schools where pupils made significantly less progress.
Examples for KS2 to 3 CVA:
- a measure of 100.6 with a CI between 99.8 and 101.4 means the progress made by pupils in the school's KS3 cohort is not significantly different from the national average
- a measure of 101.5 with a CI between 100.9 and 102.1 means the progress made by pupils in the school's KS3 cohort is significantly above the national average
- a measure of 99.2 with a CI between 99.0 and 99.4 means the progress made by pupils in the school's KS3 cohort is significantly below the national average.
Further information on the calculation and interpretation of CVA measures and confidence intervals can be found in the "CVA Guide 2007" on this website.
CVA percentiles
The CVA percentiles give the distribution of CVA scores and show where schools are placed nationally compared to other schools, based on the CVA measure. There are three versions, which allow comparisons against: all schools (i.e. both mainstream and special); mainstream schools only; and special schools only.
Key Stage 2 to 3 CVA Measure (centred around 100)
| Profiles | Percentiles | ||
|---|---|---|---|
| All Schools | All Maintained Mainstream Schools | All Special Schools | |
| 101.6 and above | 101.5 and above | 102.8 and above | Top 5% of schools nationally |
| 100.6 to 101.5 | 100.6 to 101.4 | 100.9 to 102.7 | Next 20% of schools nationally |
| 100.1 to 100.5 | 100.3 to 100.5 | 100.0 to 100.8 | Next 15% of schools nationally |
| 99.9 to 100.0 | 99.9 to 100.2 | 99.3 to 99.9 | Middle 20% of schools nationally |
| 99.4 to 99.8 | 99.5 to 99.8 | 99.0 to 99.2 | Next 15% of schools nationally |
| 98.6 to 99.3 | 98.5 to 99.4 | 98.7 to 98.9 | Next 20% of schools nationally |
| 98.5 and below | 98.4 and below | 98.6 and below | Bottom 5% of schools nationally |
Snake plots are a useful way of presenting percentiles. The following three plots simply repeat the information shown in the table above but in a way that enables the national distribution to be more easily understood.
All schools
All Maintained mainstream schools
All Special schools (including non-maintained)
