Does anyone know the effect of age standardisation - actual figures, standardisation table.
My current estimate is that starting with a September birthday, add approx 1.5 marks for each month until you get to birth month of your child.
Does anyone have some accurate data?
The effect of age standardisation is dependant on a number of factors including:-
1. Type/Compiler of the exam.
2. The cohort
3. The number of questions in a particular age standardisation
4. The difficulty of the particular questions.
However you can guess based on previous years and/or similar exams.
The Warwickshire exam is set by the Univ of Durham CEM - the same organsisation that sets the B/Ham KE grammar exams. These exams tend to be in the difficult category.
If you take a look at the following post in the B/ham section you will get an idea of the impact of age on the raw scores required to achieve a Standardised score of 118.http://www.elevenplusexams.co.uk/forum/11plus/viewtopic.php?t=14057&postdays=0&postorder=asc&start=10
In that particular KE exam for the VR section there was a difference of 6 in the raws scores at the extremes of age for 100 questions 65/100= 118 and 71/100=118.
So I think you estimate of 1.5 marks per month is too high, this would suggest 1 raw mark for every 2 months for 100 VR questions on that particular exam and section.
So Mattsurf's figure of 2-3% is a good approximation at the extremes of Age
You need to remember that the Age Standardisation process is based on a mathematical/statistical procedure.
The government (DCSF) has produced a very good research paper which gives the differences in the statistical metrics for a range of different age standardised tests, including 11+ exams, CATs, MidYis etc.
Hope this helps