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TECHNICAL ANNEX
Introduction
This Annex describes the methods that have been used to construct the value added measures for the
schools that volunteered to take part in the pilot.
This annex is split into two sections, the first explaining the calculation of the KS2 to KS3 value added
measure and the second 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 these measures should be interpreted.
KS2 TO KS3 VALUE ADDED MEASURE
Pupils included
The value added measure for KS2 to KS3 is based on the results achieved by pupils:



who were eligible for KS3 assessment in 2001; and
who were on the roll of the school at the time of tests (May 2001); and
for whom there was a match to prior attainment in KS2 tests.
Allocation of points to KS2 and KS3 results
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.
Allocation of point scores
KS2
Test outcome (level)
All subjects
6
39
5
33
4
27
3
21
Compensatory 2
15
B (working below the level of the test)
15
N (not enough marks achieved to award a level)
15
Disapplied
Disregarded
Absent
Disregarded
Lost script
Disregarded
Ineligible
Disregarded
KS3
Test outcome (level)
English
Maths and Science
E (exceptional performance)
57
57
8
51
51
7
45
45
6
39
39
5
33
33
4
27
27
3
21
21
-
15
B
21
15
N
21
15
Disapplied
Disregarded
Disregarded
Absent
Disregarded
Disregarded
Mixed tier (maths and science only) Disregarded
Disregarded
Lost script
Disregarded
Compensatory 2
Disregarded
Ineligible
Disregarded
Disregarded
Pupils for whom all results were disregarded at KS2 or KS3 have been excluded from the value added
calculations - except those pupils with at least one disregarded result which was disapplied at KS2 and at
least one KS3 result which is not disregarded: such pupils will be included in the calculation with an input
score of zero.
Input measure (KS2)
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:
27 + 27 + 33
= 29
3
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 (KS3)
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 test
levels 5, 6 and 4 in English, mathematics and science respectively would be:
33 + 39 + 27
= 33
3
If any KS3 results for a pupil are disregarded, the output measure is calculated as the average of the
remaining non-disregarded results.
Calculation of a pupil's value added 'score'
A pupil's value added score is based on 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 an average KS3 average point score at or below the median, and half at or above the
median.
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
special schools only and the other shows median scores for all other pupils.
The median KS3 point scores are also given in the tables below: one table gives the medians for mainstream
schools and the other gives the medians for special schools.
Mainstream schools
KS2 average point score National Median KS3 average point score
0
21
15
21
17 - 18
21
19
24
21
27
23 -24
29
25
33
27
35
29 - 30
39
31
41
33 +
43
Special schools
KS2 average point score National Median KS3 average point score
0
15
15
17
17 - 18
21
19
21
21
23
23 +
27
Calculation and presentation of a school's value added (KS2 to KS3)
In the following example, school A has 4 pupils eligible for inclusion in the value added pilot 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:
Pupil's KS2 average Pupil's KS3 average Median KS3 average point score
Pupil's value
Pupil
point score
point score
for their KS2 average
added score
A
25
36
33
+3
B
25
29
33
-4
C
27
35
35
0
D
27
37
35
+2
Total of all pupils' value added scores = +1
Average value added score per pupil = +1 divided by 4 (the number of pupils)
Schools value added score
= +0.25
The value added measure (KS2 to KS3)
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:
= 0.25 + 100 = 100.25
= 100.3 (rounded to one decimal place using normal rounding conventions)
KS3 TO GCSE/GNVQ VALUE ADDED MEASURE
Pupils included
The value added measure for KS3 to GCSE/GNVQ is based on the results achieved by pupils:



who were 15 years old on 31 August 2000; and
were on the school roll on 18 January 2001; and
for whom there was a match to prior attainment in KS3 tests.
Allocation of points to GCSE/GNVQ results
The 'input' and 'output' measures for the value added calculations are based on the points awarded to pupils'
results. The following tables show how points are allocated to pupils' GCSE/GNVQ results.
Grade GCSE points GCSE (Short Course) points
A*
8
4
A
7
3.5
B
6
3
C
5
2.5
D
4
2
E
3
1.5
F
2
1
G
1
0.5
GNVQ grade
Full GNVQ Part One GNVQ GNVQ Language Unit
Intermediate Distinction
30
15
-
Intermediate Merit
24
12
-
Intermediate Pass
20
10
3.5
Foundation Distinction
16
8
-
Foundation Merit
12
6
-
Foundation Pass
6
3
2
Point scores for KS3 results can be found in the KS2 to KS3 value added section of this annex.
Input measure (KS3)
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:
27 + 27 + 33
= 29
3
If any KS3 results for a pupil are disregarded, the output measure is calculated as the average of the
remaining non-disregarded results.
Output measure (GCSE/GNVQ)
The output measure for each pupil is the total point score at GCSE/GNVQ. This is based on the sum of all
points attained by a pupil. For example, a pupil who achieved 7 Cs, 2 Bs and 2 As at GCSE has a total point
score of 61.
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 KS3. 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 KS3 point scores
nationally - joining the medians gives the 'national median line'. There are two graphs: one shows median
scores for pupils in special schools only and the other shows median scores for all other pupils.
The median GCSE/GNVQ point scores are also given in the tables below: one table gives the medians for
mainstream schools and the other gives the medians for special schools.
Mainstream schools
KS3 average point score National Median total GCSE/GNVQ point score
0 - 18
6
19
9
21
11
23 - 24
16
25
21
27
26
29 - 30
32
31
37
33
42
35 - 36
47
37
52
39
57
41 - 42
61.5
43
66.5
45
70.5
47 - 48
74.5
49
77
51+
77
Special schools
KS3 average point score National Median total GCSE/GNVQ point score
0 - 18
3
19
3
21
4
23 - 24
6
25
8
27
8
29 - 30
11
31+
17
Calculation and presentation of a school's value added (KS3 to GCSE/GNVQ)
In the following example, school B has 4 pupils eligible for inclusion in the value added pilot 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:
Pupil's KS3
Pupil's total
Median total GCSE/GNVQ point
Pupil's value
Pupil
average point
GCSE/GNVQ point
score for their KS3 average
added score
score
score
A
29
32
32
0
B
33
41
42
-1
C
33
38
42
-4
D
43
65
66.5
-1.5
Total of all pupils' value added scores = -6.5
Average value added score per pupil = -6.5 divided by 4 (the number of pupils)
School's value added score
= -1.625
The value added measure (KS3 to GCSE/GNVQ)
The value added measure will be presented in the pilot publication as a measure centred around 100 - i.e. by
adding 100 to a school's value added score. For example, the value added measure for the school illustrated
above is:
= -1.625 + 100 = 98.375
= 98.4 (- rounded to one decimal place using normal rounding conventions)
Calculation of average number of GCSE/GNVQs taken by pupils in value added calculation
This shows the average number of GCSE/GNVQs taken by each pupil included in the value added
calculation. It is calculated by summing the number of GCSE/GNVQs taken by each pupil and dividing this by
the number of pupils included in the calculation, based on the equivalencies between GCSEs and GNVQs as
set out in the following table:
Equivalent to:
Qualification
No. of GCSEs GCSE grades
GNVQ Part One
Intermediate
2
A*-C
Foundation
2
D-G
Intermediate
4
A*-C
Foundation
4
D-G
GNVQ Full
GNVQ Language Unit
Intermediate
½
A
Foundation
½
D
For example, a school has 10 pupils who are included in the calculation and the number of GCSE/GNVQs
taken by each of the pupils is as follows:
Pupil Number of full
Number of GCSE short Number and type of
Equivalent number
GCSEs taken
courses taken
GNVQs taken
of GCSEs
1
8
0
0
8
2
9
0
0
9
3
10
0
0
10
4
5
2
0
6
5
6
4
0
8
6
4
1
1 Full GNVQ
8.5
7
0
0
2 Full GNVQs
8
8
0
0
1 Part 1 GNVQ and 2 Full
GNVQs
10
9
1
1
2 Full GNVQs
9.5
1 Part 1 GNVQ and 1 GNVQ
4.5
Language Unit
The calculation in this example for the average GCSE/GNVQs taken by pupils would be:
8 + 9 + 10 + 6 + 8 + 8.5 + 8 + 10 + 9.5 + 4.5
= 8.15
10
For publication, this is rounded to one decimal place and shown as 8.2, using normal rounding conventions.
10
0
4
How the mobility indicator is calculated
This shows the proportion of pupils that have remained in a school between KS3 and GCSE/GNVQ. It is
calculated by dividing the number of pupils who took both their KS3 and GCSE/GNVQ tests/examinations in
the school by the total number of pupils included in the value added calculation. For example, if a school had
10 pupils and only 7 took both their KS3 and GCSE/GNVQ tests and examinations in the same school then
the mobility indicator would be:
7
x 100 = 70%
10
Interpretation of a school's value added measure
The value added scores are shown as a measure centred around 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 the KS2 to KS3 value added measure, a score of 101 means that on average each of the school's pupils
made a sixth of a National Curriculum level more progress between KS2 and KS3 than the median for pupils
with similar KS2 attainment. This represents approximately one term's extra progress. Conversely a score of
99 means that the school's pupils made a term's less progress.
For the KS3 to GCSE/GNVQ measure, a score of 101 means that on average each of the school's pupils
achieved one extra GCSE/GNVQ point than the median for pupils with similar KS3 attainment. Conversely a
score of 99 means that the school's pupils achieved one fewer GCSE/GNVQ point.
The degree of significance which can be attached to any particular school's value added measure depends,
among other factors, on the number of pupils included in the value added calculation. The smaller the number
of pupils, the less confidence can be placed on the value added measure as an indicator of whether the
effectiveness of a school is significantly above or below average. As a guide:


at KS2 to KS3, with schools of 50 or more pupils in the value added measure, scores of 99.1 to 100.9
represent broadly average performance while for schools with 100+ pupils, scores of 99.3 to 100.7 are
broadly average;
at KS3 to GCSE/GNVQ, with schools of 50 or more pupils in the value added measure, scores of 97.2
to 102.8 are broadly average while for schools with 100+ pupils, scores of 98.0 to 102.0 are broadly
average.
When comparing the measures for two schools a similar effect holds:


at KS2 to KS3 when comparing schools with cohorts of about 50 pupils, differences of up to 1.3 should
not be regarded a statistically significant, while for schools with about 100 pupils, differences up to 0.9
should not be regarded as significant;
at KS3 to GCSE/GNVQ when comparing schools with cohorts of about 50 pupils, differences of up to
4.0 should not be regarded as statistically significant, while for schools with about 100 pupils,
differences up to 2.8 should not be regarded as significant.
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 10 pupils included in either of the value added measures, only
scores of below 97.7 or above 102.3 are likely to be significantly different from the average.
The coverage indicators also give some indication of schools where the value added measures 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 school value
added calculation.
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