Secondary School Performance Tables 2002

VALUE ADDED TECHNICAL INFORMATION

Introduction

This annex describes the methods that have been used to calculate the KS2 to KS3 and the KS3 to GCSE/GNVQ value added measures.

The annex is split into two sections: the first explains the calculation of the KS2 to KS3 value added measure; the second explains the calculation of the KS3 to GCSE/GNVQ value added measure. The two sections are similar in format and include details of how each school's value added measure has been calculated as well as how the measures should be interpreted.

Key Stage 2 to Key Stage 3 value added measure

Pupils included

The KS2 to KS3 value added measure is based on the results achieved by pupils:

• who were eligible for KS3 assessment in 2002; and
   
• who were on the roll of the school at the time of the tests (May 2002); and
   
• for whom we were able to match prior attainment in KS2 tests.
   

All pupils for whom all results are disregarded at KS2 or KS3 have been excluded from the value added calculation, with one exception: if a student was disapplied in all three subjects or had a combination of disapplied and disregarded results at KS2 and achieved at least one KS3 result at levels 2-7, then he/she was included in the calculation with an input score of zero.

Key Stage 2 test results: Allocation of point scores

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' KS2 and KS3 results.

Key Stage 2

KEY STAGE 3

Input measure (Key Stage 2)

The input measure for each pupil is calculated as the average point score achieved in the English, mathematics and science KS2 test results. For example, the average point score for a pupil achieving test levels 4, 4 and 5 in English, mathematics and science respectively would be:

If any KS2 results for a pupil are disregarded, the input measure is calculated as the average of the remaining non-disregarded subjects.

Output measure (Key Stage 3)

The output measure for each pupil is calculated as the average point score achieved in the English, mathematics and science KS3 test results. For example, the average point score for a pupil achieving levels 5, 6 and 4 in English, mathematics and science respectively would be:

If any KS3 results for a pupil are disregarded, the output measure is calculated as the average of the remaining one or two results.

Calculation of a pupil's value added score

A pupil's value added score is calculated by comparing their KS3 performance with the median KS3 performance of other pupils with the same or similar prior attainment at KS2. The median value is the middle value - with half of the pupils having a KS3 average point score at or below the median, and half at or above it.

The graphs below give the median KS3 point scores across the range of KS2 point scores nationally - joining the medians gives the 'national median line'. There are two graphs: one shows median scores for pupils in mainstream schools and the other shows median scores for pupils in special schools only.

The national Key Stage 2 - Key Stage 3 median scores are shown in the tables below. Table A lists median scores for students in mainstream schools and Table B lists median scores for students in special schools.

Table A: Mainstream schools

Table B: Special schools

Calculation and presentation of the Key Stage 2 to Key Stage 3 value added measure

In the following example, school A has four pupils eligible for inclusion in the value added measure with KS2 and KS3 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 score is a simple average (arithmetic mean) of the value added measures for all pupils in the school. For example for a mainstream school:

The value added score for each school has been published in terms of a measure centred 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:

Calculation of the Key Stage 2 to Key Stage 3 coverage indicator

The coverage indicator has been published as a percentage and is based on the number of pupils eligible for KS3 tests in 2002 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. For example, if a school had 10 pupils who were eligible for KS3 assessment in 2002, but two of those pupils were not included in the value added calculation, then the number of pupils included in the value added score would be 8. The coverage indicator in the example would be:

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

Key Stage 3 to GCSE/GNVQ value added measure

Pupils included

The KS3 to GCSE/GNVQ value added measure is based on the results achieved by pupils:

• who were 15 years old on 31 August 2001; and
   
• were on the school roll on 17 January 2002; and
   
• for whom we were able to match prior attainment in KS3 tests.

All pupils for whom all results are disregarded at KS3 will be excluded from the value added calculations, with one exception: if a student was disapplied in all 3 subjects or had a combination of disapplied and disregarded results at KS3 and achieved at least one GCSE/GNVQ at grade A*-G, then he/she will be included in the calculation with an input score of zero.

Allocation of points: GCSE/GNVQ results

GNVQ: Equivalence to GCSE and allocation of points

Point scores for KS3 results can be found in the KS2 to KS3 value added section of this annex.

Input measure (Key Stage 3)

The input measure for each pupil is calculated as the average point score achieved in the English, mathematics and science KS3 test results. For example, the average point score for a pupil achieving test levels 4, 4 and 5 in English, mathematics and science respectively would be:

If any KS3 results for a pupil are disregarded, the output measure is calculated as the average of the remaining one or two results.

Output measure (GCSE/GNVQ)

The output measure for each pupil is capped at a pupil's best eight GCSE/GNVQs.

Calculation of capped GCSE/GNVQ point score

In order to calculate the capped GCSE/GNVQ point score for each pupil, each qualification has been divided into records to show its equivalence to the smallest qualification, which is a GCSE (Short Course) and has half the weight of a full GCSE as shown below:

The point score allocated to each result is also divided by the number of records. For example, a pupil who achieved 3 Bs and 3Cs at GCSE, an A* for a GCSE (Short Course) and a full Intermediate GNVQ with distinction would have their results broken down and their capped GCSE/GNVQ point score calculated in the following way:

Only the 16 highest scoring records (i.e. the best 8 GCSEs/GNVQs) are used to calculate a pupil's point score. In this case the lowest five records worth 2.5 points each and representative of two and a half GCSEs at grade C are disregarded. In this example the pupil's point score is 54.50.

The average capped point score per pupil for your school is calculated by dividing the overall number of points (capped as described above) by the number of pupils.

Calculation of a pupil's value added score

The pupil's value added score is based on comparing their GCSE/GNVQ performance with the median GCSE/GNVQ performance of other pupils with the same or similar prior attainment at Key Stage 3. The median value is the middle value - with half of the pupils having a total GCSE/GNVQ point score at or below the median, and half at or above.

The graphs below give the pattern of median GCSE/GNVQ point scores across the range of Key Stage 3 point scores nationally - joining the medians gives the 'national median line'. There are two graphs: one shows median scores for mainstream schools and the other shows median scores for pupils in special schools only.

The national Key Stage 3 - GCSE/GNVQ median scores are shown in the tables below. Table A lists median scores for students in mainstream schools and Table B lists median scores for students in special schools.

Table A: Mainstream schools

Table B: Special schools

Calculation and presentation of a school's value added (Key Stage 3 to GCSE/GNVQ)

In the following example, school B has four pupils eligible for inclusion in the calculation with KS3 and GCSE/GNVQ average point scores. 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 score is a simple average (arithmetic mean) of the value added measures for all the pupils in the school. For example, for a mainstream school:

School's value added scores have been published in terms of a measure based around 100 - i.e. by adding 100 to the school's value added score. In the example above, the value added score for school B would be shown as:

The coverage indicator

This shows, as a percentage, the proportion of pupils included in the KS3 to GCSE/GNVQ value added calculation. For example, if a school had 10 pupils aged 15 on roll but only 6 of them were included in the value added measure then the actual number of pupils included in the value added score would be 6. The coverage indicator in this example would be:

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

Average number of GCSE/GNVQs taken by pupils in the value added calculation

This shows the average number of GCSE/GNVQs taken by each pupil included in the value added calculation. It has been calculated by dividing the total number of GCSE/GNVQ examinations taken by each pupil by the number of pupils included in the calculation. The total number of examinations has been determined using the table of GCSE and GNVQ equivalencies set out in the first part of this annex.

For example, a school has ten pupils who are included in the calculation and the number of GCSE/GNVQs taken by each of the pupils is as follows:

The calculation in this example for the average number of GCSE/GNVQs taken by pupils would be:

This would be rounded to 8.2 using normal rounding conventions.

The stability indicator

This shows the percentage of pupils included in the value added calculation who took both their KS3 tests and GCSE/GNVQs in the same school. For example, if a school has 10 pupils in the value added calculation and only 7 took both their KS3 tests and GCSE/GNVQ examinations in the same school, then the stability indicator would be: