I haven't read any of this thread at all - I daren't! However, apparently one of you lovely MNetters has asked about value added statistics so thought that I would jump in and explain a little bit.
A bit of context - I am a Year Six teacher and head of year in a large school and have a key role in the organising and preparation of SATs and the analysis of data.
VAlue added is a measure of how much 'extra' a school gives its pupils - for example, a pupil may be prdicted a low level 4 at key stage two (based upon what they achieved at KS!)but might achieve a high level 4 - so the value added it the extra bit (low L4 to high L4) that the school have added on.
There are all the usual arguements about pupils progressing at different rates....but the main flaw (as i see it) is the way that it is calculated. I am going to simplify this a little or I will get myself tied up in knots.....
Bear with me if you are interested!
Pupils are 'expected' to achieve level 4 at KS2 - they are given a prediction based on their KS1 sats adding half a level a year - so a pupil who achieves l2 at KS1 is predicted a L4 at ks2.
Levels are assigned points scores so say
L1 =1 point
L2 = 2 points
L3 = 3 points (etc - not correct but illustrates the point)
A child with 3 points in each subject at KS1 will obviously get a total of 9 points....they are therefore predicted 3 level 5s at ks2 (15 points) but to get a positive value added total they need to get more than 15 points - more than 3 level 5s
BUT THEY CANNOT GET THIS AS LEVEL 5 IS TEH HIGHEST YOU CAN ACHIEVE AT KS2.
So if the school has good results at KS1 - ie lots of level 3s and therefore lots of children working ABOVE average - lots of children will be predicted level 5s at KS2. It is impossible to get a high value added score as there is currently no way to measure value added with these pupils.
So a really good school will have a value added measure of around 100 (as predicted so to speak) when many of the pupils are above average.
Does that make any sense?
That is the first flaw....