VALUE ADDED MEASURES

What do we mean by value added?

Some pupils will find it particularly difficult to do well in tests and examinations. It may be, for example, that they have significant special educational needs. 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.

Value added measures are intended to allow fairer comparisons between schools with different pupil intakes. We publish two value added measures in these Tables: a KS2 to KS4 value added measure and a KS3 to KS4 value added measure. The KS2 to KS4 value added measures the progress that individual pupils at the end of KS4 - i.e. in Year 11 - have made since taking their KS2 tests in Year 6 (generally aged 11). This measure looks at the progress that pupils have made for the whole secondary phase of education, whereas the KS3 to KS4 value added measure shows the progress pupils at the end of KS4 have made since taking their KS3 tests in Year 9..

For example, school A might show higher percentages of pupils achieving Level 2 qualifications (five or more GCSE grades A*-C, or equivalent) than school B. But school A's pupils may have done far better in their key stage tests than school B's. For the KS2 to KS4 value added measure, each school's pupils are compared individually with other pupils with similar KS2 test results. If they do better than the median - or middle - performance of other pupils in their GCSE (and equivalent) examinations, the value added will be positive; if they do less well than other pupils, it will be negative. All the individual pupil scores, positive and negative, are added together and averaged to form the school's measure.

If school A's pupils generally made less progress than the average for pupils with similar KS2 results, and school B's pupils generally made more progress than the average for pupils with similar KS2 results, then school B will have higher value added than school A, even though school B's percentage of pupils achieving Level 2 qualifications is lower.

Value added scores

We base each pupil's value added score on a comparison between their best eight results at GCSE and equivalent - sometimes referred to as their capped point score - and the median or middle performance of other pupils with the same or similar results at the relevant key stage (either KS2 or KS3). The individual pupil scores are added together and averaged to produce the school level VA measure. This number is presented as a number based around 1000. This indicates the value the school has added on average for its pupils. Independent schools may choose not to have their value added measures published, as they are not obliged to follow the National Curriculum.

A more detailed explanation on how value added measures are calculated for a school, including how to work out a pupil's best eight results when they have taken a mix of different qualifications can be found in the Value Added Technical Information section on the Achievement and Attainment Tables website at www.dcsf.gov.uk/performancetables/schools_05.shtml

Interpretation of a school's value added measure

The value added scores are shown as measures based around 1000 for both
KS2 to KS4 and KS3 to KS4. Measures above 1000 represent schools where pupils on average made more progress than similar pupils nationally, while measures below 1000 represent schools where pupils made less progress.

For each of the KS4 value added measures, a measure of 1006 means that on average each of the school's pupils achieved the equivalent of one GCSE grade higher in one subject than the median - or middle value - for pupils with similar prior attainment. A score of 1048 means that on average each pupil achieved one GCSE grade higher in each of their best eight subjects than the median pupil. Conversely, a score of 994 means that the school's pupils achieved one grade lower in one subject on average, while a score of 952 means that pupils achieved on average one grade lower in each of their best eight subjects than the median pupil.

What a school's value added measures tell you

Key Stage 2 to Key Stage 4 value added measure

As a guide, the tables below show scores that are broadly average based on the size of the cohort for pupils included in the Key Stage 2 to Key Stage 4 value added measure.

Mainstream schools

For cohorts of about 200 pupils, differences of up to 14.4 should not be regarded as significant. For cohort of about 100 pupils, differences of up to 20.4 should not be regarded as significant. When comparing schools with cohorts of about 50 pupils, differences of up to 28.9 should not be regarded as significant. Particular care should be taken with the results for schools where cohort sizes are smaller than this, and even quite large differences may not be significant.

Special schools

When comparing special schools with cohorts of about 20 pupils, differences of up to 28.5 should not be regarded as significant. For schools with about 10 pupils, differences of up to 40.3 should not be regarded as significant.

Key Stage 3 to Key Stage 4 value added measure

As a guide, the tables below show scores that are broadly average based on the size of the cohort for pupils included in the Key Stage 3 to Key Stage 4 value added measure.

Mainstream schools

For cohorts of about 200 pupils, differences of up to 13.3 should not be regarded as significant. For cohorts of about 100 pupils, differences of up to 18.9 should not be regarded as significant. When comparing schools with cohorts of about 50 pupils, differences of up to 26.7 should not be regarded as significant. Particular care should be taken with the results for schools where cohort sizes are smaller than this, and even quite large differences may not be significant.

Special schools

When comparing special schools with cohorts of about 20 pupils, differences of up to 27.4 should not be regarded as significant. For schools with about 10 pupils, differences of up to 38.7 should not be regarded as significant.

Value added profiles

By looking at the tables below, you can see how the VA measures for a school compare to those of other schools nationally.

Coverage

The coverage column shows the percentage of pupils at the end of KS4 included in the KS2 to KS4 value added calculation. This gives some indication of schools where the value added measures may be unrepresentative. A low percentage means that information was not available to calculate the value added scores of many of the school's pupils, and so these pupils could not be included in the value added calculation. Where coverage is less than 50%, the value added measure has not been published.

Future improvements to value added measures

The value added measures in the current Tables take account of prior attainment (results at the end of Key Stage 2 and 3), which is the biggest single factor affecting pupil results. However, other factors outside a school's control, such as gender, mobility and levels of deprivation, have been observed to have a further impact on pupil results, even after allowing for prior attainment. Taking these additional factors into account requires a more complex model, which we are in the process of developing and introducing, for use by the Department and Ofsted. We call this measure Contextual Value Added (CVA).

The 2005 Pupil Achievement Tracker and Ofsted's PANDA reports both include CVA measures. In future years we will be bringing CVA measures into the Achievement and Attainment Tables. We have piloted these with secondary schools in 2005, so that they can be in the Secondary School Achievement and Attainment Tables in 2006. Further information on the Contextual Value Added Pilot can be found on the Tables website: www.dcsf.gov.uk/perfomancetables