How scaling works and why is often misunderstood. Let me see if I can help explain a few things about how it works.
1. A hard exam has no impact on scaling. The raw study score (ie pre scaling) is a ranking. A hard exam impacts everybody's ability to get a high exam mark, but it doesn't make it any harder to achieve any given ranking (raw study score).
2. Scaling up (or down) is meant to compensate for the fact that it is relatively more (or less) difficult to achieve a given ranking in a study where the cohort undertaking that subject is more (or less) intelligent than it is for other subjects. It is nothing to do with the difficulty of the subject or of the exam.
3. The impact on scaling of all Maths Methods students doing the CAS version this year for the first time is likely to be minimal. The fact that the cohort this year is different (ie is a combined pool of all the previous CAS and non CAS) could in theory result in a different scaling factor being applied. This would occur if the combined cohort was more or less intelligent than the old CAS cohort. However, the scaling report for 2009 shows that the scaling for both CAS and non CAS was identical. This would indicate that there is very little difference in the cohorts and so the combined cohort this year would not be likely to warrant a different scaling factor.
4. My personal view is that I am very sceptical of the accuracy of scaling and the ability of VTAC to measure what is the "right" scaling factor to apply. I say this because I find it very hard to believe how little the scaling factors applied to each subject differ from year to year. I would expect that the fact that each year a completely different group of students undertakes each subject would cause significant variation in the scaling factor for each subject from year to year. Is it really likely that the relative intelligence of students taking such diverse subjects as psychology, maths, outdoor ed, art, dance, languages, accounting etc etc is so consistent from year to year ? Every year, bus management gets scaled down by the same amount, further maths goes down by the same amount, and so on. Seems very unlikely that this is the result of an accurate measure of the relative intelligence of each subject's cohort, and the result is almost identical each year. What it says to me is that they haven't really got much of a handle on it at all, and they just apply the same factor they have in the past !!
I guess the beauty of it is that no-one knows if they are being dudded or whether they are benefitting!!