ih8exams said:
Why would you subtract 20 from a harder course and add 20 for an easier course. Wouldnt this just makes the subjects equal pretty much which is once again unfair to those who took the harder subjects???
You can add and subtract whatever marks you want from whatever courses you like, and it will make no difference to how everything is scaled - it was just an example.
ih8exams said:
As for it being a new system, it is, as the changes in scaling has changed since then. Harder subjects were always scaled higher(either this or we have been misled by many media and school articles)
Harder courses aren't scaled higher because they are harder. They're scaled higher because they're taken by better students. If a course is taken by better students, it makes it harder for an average student to obtain a good rank in the course (because they're competing against above average students). The UAI is all about ranking students.
If you convinced all the Mathematics Extension 2 students to take Food Technology, and all the Food Technology students to take Mathematics Extension 2 (i.e. swapping the candidatures), the scaling parameters for each course would be swapped as well - even if they all had really low raw marks!
ih8exams said:
Like a friend of mine who pushed himself to do the hard subjects did quite well, all in 70s and one in the 80s but ends up with a uai in the 60s.
The marks themselves are completely irrelevant. It doesn't matter whether he gets all 70s, all 80s, or all 90s. What matters is how many other students he beat in each course. If you take a 'hard' course and get 90, but everyone else gets 95, you actually haven't done that well - unless everyone else was just really smart, which would justify some positive scaling (tough competition makes it hard to get a high rank).
If you take an 'easy' course and only get 50, but everyone else only gets 40, you actually haven't done that poorly - unless everyone else was just 'less smart', which would justify some negative scaling (it was too easy for an average student to get a high rank).
And this is how the system works. Aside from the issue mentioned by Rench, it isn't flawed in any of the ways you have pointed out.