I think there may be confusion here between scaling and moderation? Or maybe it's just me that's confused.
Nope, it's just you

........only kidding. I'm not sure if there's a difference?
Moderation is the process of eliminating or lessening extremes. (hence your English SACS are checked by more than 1 teacher)
for the STUDY SCORE however, I think SCALING is used.
For example, in Economics in 2007 the average VCE Study Score was 30, but the students averaged 32 for all their studies. This shows that the students who did Economics in 2007 were of above average strength in their other studies. Therefore the scaling process adjusted the Study Scores upwards so that the
VTAC adjusts the Study Scores for each study to take account of how strong the students were in the study and
how difficult it was to achieve the middle ranking. The strength of competition in each study is measured by how well the students performed in all their studies.
But that's weird, you know how it says, it scales according to how you did in your other subjects? But how come in eco, and other subjects, they ALWAYS tend to be scaled up, there must be SOME years when people who did eco did bad in other subjects? But we always understand the sciences, and eco, etc to be scaled UPWARDS. I am missing a point here :S