The development of the tests involves extensive pre-testing, from which we obtain data about the difficulty of the questions in relation both to the previous year and to similar questions at other key stages. We also carry out a structured exercise with groups of teachers to collect their expert views on the difficulty of the tests. These various sources of data give us a narrow range of marks within which each level boundary can be set in order to reflect the correct standards.
Where the pre-test data have given us a choice of marks within a narrow range, we are double-checking the level boundaries by looking at the marks awarded on a national sample of 10,000 pupils before confirming them. Our scope for making changes cannot go beyond the narrow range of marks which our pre-test data has already established. The process is exactly analogous to the final setting of grade boundaries in public examination such as GCSE and A-level.
We are inviting a number of independent experts, including representatives of the teacher associations, to observe the exercise.
Our willingness to be open about this is the best response to your conspiracy theory suggestion that there will be political interference in setting levels. But of course, the truth rarely deserves a front-page story.
NICHOLAS TATE Chief executive School Curriculum and Assessment Authority Notting Hill Gate, London W11