VALUE ADDED TECHNICAL INFORMATION

Introduction

Value added is a measure of the progress students make between different stages of education. This document explains how value added has been calculated for each student and then aggregated to give a score for the school. In order to calculate this we use a median line approach whereby the value added score for each student is the difference (positive or negative) between their own 'output' point score and the median - or middle - output point score achieved by others with the same or similar starting point, or 'input' point score. In this way an individual student's progress is compared with the progress made by other students with the same or similar prior attainment. The value added scores show how schools have helped students at the end of compulsory school age progress since taking their Key Stage 2 tests (KS2 to Age 15 value added measure) and since taking their Key Stage 3 tests (KS3 to Age 15 value added measure).

For each value added measure there are two separate value added median lines, based on individual student value added scores ; one for mainstream schools and one for special schools.

This document also describes the calculation of the school's capped average point score and the contextual information shown with the value added measure.

Students included

The KS2 to Age 15 value added measure is based on the results achieved by students:

• who were 15 years old on 31 August 2003;
• who were on the school roll on 15 January 2004; and
• for whom we were able to match prior attainment in KS2 tests.

The KS3 to Age 15 value added measure is based on the results achieved by students:

• who were 15 years old on 31 August 2003;
• who were on the school roll on 15 January 2004; and
• for whom we were able to match prior attainment in KS3 tests.

All students for whom all results are disregarded at KS2 or KS3 will be excluded from the value added calculations, with one exception: if a student was disapplied in all three subjects or had a combination of disapplied and disregarded results at KS2 or KS3 and went on to achieve at least an entry level qualification at age 15, then he/she will be included in the calculation with an input score of zero.

The following paragraphs explain how the KS2 to Age 15 value added measure is calculated. The methodology used to calculate the KS2 to Age 15 and KS3 to Age 15 value added measures is the same, although the input measure for the KS3 to Age 15 value added measure would be based on the KS3 test results and its corresponding point scores as outlined in the tables that follow.

Allocation of point scores for prior attainment

The following tables show how points are allocated to students' KS2 and KS3 results.

Key Stage 2 test results: Allocation of point scores

Key Stage 3 test results: Allocation of points

** Disregarded means these results will not contribute towards the average point scores per student for value added purposes.

Input measure (Key Stage 2)

The input measure for each student 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 student, achieving test levels 3, 3 and 4 in English, mathematics and science respectively would be:

(21 + 21 + 27)/3 = 23

If any KS2 results for a student are disregarded, the output measure is calculated as the average of the remaining one or two results.

Output measure (Results for 15 year olds)

The output measure for each student is the sum of the point scores for a student's best eight GCSE (and equivalent) qualifications.

Calculation of a student's value added score

The student's value added score is based on comparing their capped point score in GCSE (and equivalent) qualifications with the median capped point score of other students with the same or similar prior attainment at Key Stage 2. The median value is the middle value - with half of the students having a capped point score at or below the median, and half at or above the median.

The graphs below give the pattern of median capped point scores for 15 year olds across the range of Key Stage 2 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 students in special schools only.

The national KS2 to Age 15 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

The graphs below give the pattern of median capped point scores for 15 year olds across the range of Key Stage 3 point scores nationally - joining the medians gives the 'national median line'. The first graph shows median scores for mainstream schools and the second shows median scores for students in special schools only.

The national KS3 to Age 15 median scores are shown below. Table C lists median scores for students in mainstream schools and Table D lists median scores for students in special schools.

Table C: Mainstream schools

Table D: Special schools

Calculation of a school's value added measure

A school's value added measure is a simple average (arithmetic mean) of the value added scores for all students in the school. In the following example, a mainstream school has 4 students eligible for inclusion in the value added measure with Key Stage 2 and GCSE (and equivalent) average point scores as shown.

Example:

The school's value added score is presented as a measure based on 1000. This is done by adding 1000 to the score. The school in the above example would have a value added measure shown as: 1006.3 (rounded to one decimal place using normal rounding conventions)

The coverage indicator

This shows, as a percentage, the proportion of students on roll who have been included in the KS2 to Age 15 value added calculation. For example, if a school had 10 students aged 15 on roll but only 6 of them were included in the value added measure, then the coverage would be:

(6/10)X100 = 60%

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

Average number of qualifications taken by students in the value added calculation

This shows the average number of approved qualifications taken by each student included in the value added calculation. It has been calculated by dividing the total number of examinations taken by each student included in the VA measure by the number of students included in the calculation. The total number of examinations has been determined using the equivalence between GCSEs and other approved qualifications.

For example, a school has 10 students who are included in the calculation and the number of examinations taken by each of the students is as follows:

The calculation in this example for the average number of GCSE (and equivalent) examinations taken by students would be:

(8 + 9 + 10 + 6 + 8 + 8.5 + 8 + 10 + 9.5 + 4.5)/10 = 8.15

This would be rounded to 8.2 using normal rounding conventions.

National value added score

For statistical reasons, the average value added of all schools nationally is not necessarily exactly 1000. Therefore, to avoid misunderstanding by those who are unfamiliar with value added we have not published a national value added measure in the Tables. The national KS2 to Age 15 value added measure is 988.1 and the national KS3 to Age 15 value added measure is 990.7.

Calculation of capped point score

While there will be a wider range of qualifications (of varying size) included in the Tables from this year and a new scoring system used, the capping procedure will remain the same and we will continue to cap point scores at the equivalent of 8 GCSEs for use in the value added calculations. The following three steps (and examples below) describe this procedure:

Step One (see Example 1.0)

Qualifications are compared to the size of a GCSE to determine a volume indicator (i.e. the number of GCSEs a qualification is worth). For example, a GCSE in vocational subjects (Double Award) is twice the size of a GCSE so would have a volume indicator of 2.0, a short course GCSE would be 0.5.

Example 1.0 - Student results

Step Two (see Example 1.1)

The total points value for each qualification is divided by the volume indicator to arrive at a standardised points figure. For example, a GCSE in vocational subjects (Double Award) at grade B has 92 points. To arrive at the standardised points figure, we divide 92 points by the GCSE Double Award volume indicator of 2.0 (i.e. 92 divided by 2.0 = 46). The standardised point score is therefore 46.

Qualifications are then sorted in descending order based on their standardised points.

Example 1.1 - Student results in descending order

Step Three (see Example 1.2)

Once qualifications are ranked on the standardised points, the volume indicators should be summed until a total volume of 8.0 is reached. The total points for qualifications included in the cap should then be summed to arrive at the capped point score.

• N.B. The process allows for fractions of qualifications to be included in the cap should a particular qualification extend beyond the cap.

Example 1.2 - Student results capped at 8

The total capped point score becomes (58 + 26 + 92 + 40 + 119 = 335).