I have heard someone say that different schools weight different questions differently, and that is why you get different scores from different schools. But I was under the impression that the different scores from different schools was because they can choose to favour certain groups of children eg the ones who live locally. Does anyone else have an explanation for the different scores?
The apparent difference in scores has to do with standardising within the cohort who sat the exam. Because the exam is 'norm referenced' , ie a child is scored relative to others and there is no absolute pass mark in terms of questions answered, rather than criterion referenced (where a grade is given for a number of questions right, regardless of how many get that grade) then who else chooses to share scores with a school influences how well your child appears to do. An example of this happened in my own family - one of my children scored slightly lower for STRS than a friend, but slightly higher for Pates than that same friend. Clearly they only sat one exam- but the cohort was different in each case. An additional factor is the age standardisation, which while it looks a bit 'smoke and mirrors' essentially means that your child is measured against those born in the same month. Thus, again, this will be different for each school you sit for. It's done this way because it is a competitive exam - the number of people who 'pass' has to be related to the number of places available, and the 'pass mark' in each case is a notional one created by looking at the actual spread of scores. Hope this makes sense.
There is no 'weighting' of any kind- on questions, types of question or geography.