VALUE ADDED TECHNICAL INFORMATION

Introduction

This section describes the methods that have been used to calculate the KS1 to KS2 value added measure.

The KS1 to KS2 value added measure

Pupils included

The KS1 to KS2 value added measure is based on the results achieved by pupils:

• who were eligible for KS2 tests in 2005;
• who were on the roll of the school at the time of the tests (May 2005); and
• whose KS1 test results have been found

KS1 and KS2 test results: Allocation of points
The "input" and "output" measures for the value added calculation are based on the points awarded to pupils' results. The following tables show how points are allocated to pupils' KS1 and KS2 test results.

The input measure (KS1)
The input measure for each pupil is calculated as the average point score achieved in the reading, writing and mathematics KS1 task/test. However, before an average point score can be calculated, an overall reading level needs to be determined from the levels achieved in the reading task and/or the reading comprehension test.

Overall reading level
To calculate the overall reading level the following rules are applied:

• If the pupil has achieved a Level 3 or higher in the reading comprehension test, this is the level that will be used as the overall reading level.
• If the pupil has achieved lower than a Level 3 in the reading comprehension test, or was not entered for the test, the level achieved in the reading task will be used as the overall reading level.

Please see example below.

Example 1

KS1 average point score (APS)
The input measure for each pupil is the average point score achieved in the reading, writing and mathematics tests at KS1.

Please see example below.

Example 2

KS1 APS = (21+17+21)/3 = 19.67

The output measure (KS2)
The output measure for each pupil is the average point score achieved in the English, mathematics and science KS2 tests.

Please see example below.

Example 3

KS2 APS = (33+33+27)/3 = 31.0

Only the pupils for whom we have identified both KS1 and KS2 tests results in at least one subject have been included in the calculation of the value added measure. If any KS2 results for a pupil are disregarded, the output measure is calculated as the average of the remaining non-disregarded subject(s).

Calculation of a pupil's KS1 to KS2 value added score
A pupil's value added score is calculated by comparing the KS2 performance with the median KS2 performance of other pupils with the same, or similar, prior attainment at KS1. The median value is the middle value - with half of the pupils having a KS2 average point score below the median and half above the median.

The following graphs give the median KS2 average point scores across the range of average KS1 point scores for all pupils nationally - joining the medians gives the "national median line". There are two graphs: one shows median average point scores for pupils in mainstream schools and the other shows median average point scores for pupils in special schools only.

As the graphs show, pupils at the highest extremes of KS1 achievement, e.g. with an average KS1 point score of 20 or more for mainstream schools, have been grouped together. This ensures there are adequate numbers of pupils from which to calculate a robust median.

The median KS2 point scores are shown in detail in the following tables :

Calculation and presentation of a school's KS1 to KS2 value added measure
In the following example, school A has four pupils eligible for inclusion in the value added measure with KS1 and KS2 average point scores as shown. The median average point scores have been allocated according to the national median line for mainstream schools shown above, and a value added score calculated for each pupil.

A school's value added measure is a simple average (arithmetic mean) of the value added scores for all pupils in the school. See the following example for a mainstream school :

Example

Total of all pupils' value added scores = +5
Average value added score per pupil = +5 divided by 4 (number of pupils)
School's value added score = +1.25 (Calculated by dividing +5 (the total) by 4 (the number of pupils) giving +1.25.)

The value added measure (KS1 to KS2)
The value added score for each school has been published in terms of a measure based around 100 - i.e. by adding 100 to a school's value added score. In the example above the value added measure for school A is:
= +1.25 + 100 = 101.25
= 101.3 (rounded to one decimal place using normal rounding conventions)

Calculation of a school's coverage percentage
This is based on the number of pupils eligible for the KS2 tests in 2005 who were actually included in the value added calculation. It is possible that not all eligible pupils will be included in the value added calculation, because some may have been absent for all KS2 tests, and others may have no KS1 information available.

For example, if a school had 30 pupils eligible for KS2 assessment in 2005 but only 25 were included in the value added calculation, the coverage for that school would be:

(25/30) X 100 = 83%

A value added measure has not been published for schools with less than 50% coverage.