THE KEY STAGE 1 (KS1) TO KEY STAGE 2 (KS2) VALUE ADDED MEASURE

What do we mean by value added?
Some pupils will always find it difficult to do well 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 have developed a way of measuring the progress that individual pupils have made between taking assessment tests when they are generally aged 7 and in Year 2 (KS1) and assessment tests when they are generally aged 11 and in Year 6 (KS2). We call this the value added measure. Value added measures are intended to allow fairer comparisons between schools with different pupil intakes.

For example, school A might show high percentages of pupils achieving Level 4 and above, while school B shows lower percentages. But in value added terms, the pupils at school B may have made more progress than other pupils who were performing at the same level at KS1, and therefore have a higher value added "score" than school A.

The KS1 to KS2 value added measure
Each pupil's value added score is based on comparing their KS2 performance with the median - or middle - performance of other pupils with the same or similar results at KS1. The individual scores are averaged for the school to give a score that is represented as a number based on 100. This indicates the value the school has added on average for their pupils. For further information on how a value added score is calculated for a pupil and how the value added measure is calculated for a school can be found in the value added technical information section of this site

The value added measures in the current tables take account of prior attainment, which is the biggest single factor affecting pupil results. However, contextual factors which are outside the school's control, such as gender, mobility and levels of deprivation may have a further impact on pupil results, even after allowing for prior attainment. To take these into account requires a more complex model of value added. Such a model is being piloted for value added between Key Stages 2 and 4 in the 2005 Tables. Some initial trialling with schools has taken place in Autumn 2004: for more information see http://www.standards.dcsf.gov.uk/performance/pat/cva_pilot/?version=1

Interpretation of a school's value added measure

The value added scores are shown as a measure based on 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.

For KS1 to KS2 value added, a measure of 101 means that on average each of the school's pupils made one term's more progress between KS1 and KS2 than the median - or middle value - for pupils with similar KS1 attainment. Conversely, a score of 99 means that the school's pupils made a term's less progress.

Statistical Significance

Mainstream Schools

As a guide:

• at KS1 to KS2, for schools with 30 or more pupils in the value added measure, measures of 99.1 to 100.9 represent broadly average performance, while for schools with 50+ pupils, measures of 99.3 to 100.7 are broadly average.

When comparing the measures for two schools a similar effect holds:

• at KS1 to KS2 when comparing schools with cohorts of about 30 pupils, differences of up to 1.3 should not be regarded as significant, while for schools with about 50 pupils, differences up to 1.0 should not be regarded as significant.

Special schools
Particular care should be taken with the results for special schools and other schools where cohort sizes are small. For example, for special schools with 11 pupils included in the value added measure, only measures of below 98.5 or above 101.3 are likely to be significantly different from the average. When comparing special schools with cohorts of about 11 pupils, (remembering that the VA measure and KS2 results are not published for schools with 10 pupils or less) differences of up to 1.7 should not be regarded as statistically significant.

As a guide:

• at KS1 to KS2, for special schools with 20 pupils in the value added measure, scores of 98.9 to 100.9 are broadly average.

When comparing the measures for two schools:

• at KS1 to KS2, when comparing special schools with cohorts of about 20 pupils, differences of up to 1.4 should not be regarded as statistically significant.

Value Added Profiles
By looking at the table below, you can see how the VA measure for a school compares nationally.

The coverage indicator
The coverage column shows the percentage of pupils eligible for KS2 assessment that are included in the value added calculation and gives some indication of schools where the value added measure may be unrepresentative. A low coverage indicator 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. The availability of better quality prior attainment data in future years will mean that more pupils will be included in the calculation. Where coverage is less than 50%, the value added measure and the associated mobility indicator have not been published.

The mobility indicator
The mobility column shows the percentage of pupils eligible for KS2 assessment included in the value added calculation who were in the school for the whole of their KS2 education (Year 3 - Year 6 inclusive). A low mobility indicator means that a high proportion of the pupils eligible for the KS2 tests were not in the school for the whole of their KS2 education.

More detailed information about how the value added measure and the coverage and mobility indicators have been calculated can be found in the value added technical information section of this site