Um, correct me if i'm wrong, but the scaling process is similar to the ones at uni (the idea of scaling came from uni). So if a student got (a final HSC mark of) 95 in general maths and a student got 95 in extension 2 maths, then both subjects will have the same effect on your ATAR. HOWEVER, due to 4U maths being much harder than general maths the 'bell curve' for the 4U raw hsc exam will be closer to the 60-70% percent mark. The BOS/UAC then scales this unit up so the bell curve is around 80-90 (depending on how everyone in that year performed). For the general math situation, the bell curve for the raw hsc exam is much higher around 70-80. Since more students perform well in this unit, the UAC will have to scale the subject down to match the bell curve as in 4U maths. Thus in some sense, getting a 90+ mark in general maths is hard because people generally do well as a whole (i.e. your final HSC mark may be scaled down or is lower than what you scored in the raw hsc exam). This is why students who do 4U may score 80/120 but still get a final HSC mark of 90+. This is where the scaling occurs. Now how does this affect your ATAR?? By doing a subject like 4U maths enables you a higher chance get scaled up; that is, getting a higher final HSC mark than what you scored in the actual exam. This then affects your ATAR. THE SUBJECTS ALONE DO NOT SCALE YOUR ATAR. Only your final HSC marks affect your ATAR.
IN conclusion, a mark of 90 general math = a mark of 90 in 4U maths in terms of ATAR but since general is easier, your final HSC mark may be scaled down. that is, you'll get a lower hsc mark and hence it reduces the effect on your ATAR.
I have a strong feeling that this is the case but i could be wrong....please tell me if i'm wrong :O:O!....or right
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