Originally posted by CHUDYMASTER
I would like to bring to your attention that Industrial technology courses are scaled down from high forties to high thirties
This is incorrect, and demonstrates a misunderstanding of the scaling statistics.
I quote from the full 2002 report:
When reading the table it must be remembered that the Board's HSC mark indicates a standard reached whereas a scaled mark indicates a students position in the course candidature if all students had completed that course. Because HSC marks and scaled marks serve these two different purposes, comparing HSC and scaled marks is of no value, and can lead to misinterpretations that may affect student choices of courses to study.
The only way to determine whether a course was scaled up or down is to subtract 25 from the scaled mean (giving the 'course loading'). A positive loading indicates positive scaling, and, similarly, a negative loading indicates that the course was scaled down. It's impossible to say what anything was scaled from or scaled to, as no information whatsoever is known about raw marks.
Having said that, it is true that Industrial Technology was scaled down in 2003. But that's all that can be said.
Originally posted by CHUDYMASTER
Furthermore, let me just illustrate to you how unfair scaling is:
[reformatted by author - plus/minus indicates type of scaling]
My friend's marks:
1. Adv Eng 89 (+)
2. Ext Eng 48 (+)
3. Maths 92 (+)
4. Maths Ext 47 (+)
5. Economics 94 (+)
6. Ind Tech 95 (-)
His UAI = 97.85
My marks:
1. Adv Eng 93 (+)
2. Ext Eng 46 (+)
3. Maths 95 (+)
4. Maths Ext 47 (+)
5. Chemistry 90 (+)
6. Physics 91 (+)
My UAI = 99.10
Explain the justice in that?
Okay. Here we go.
I've altered the order of your courses to make this easier. The marks for the first four courses are directly comparable. Let's deal with them first.
English (Advanced) - You win.
Your mark of 93 is clearly above his mark of 89. There'd be about an 8-point difference between your percentiles.
English Extension 1 - He wins.
His mark of 48 is above your mark of 46. That difference corresponds to about 7% of the candidature. He wins here. Keep in mind that this is a 1-unit course.
Mathematics - You win.
Your mark of 95 is above his mark of 92. Again, this corresponds to beating around an extra 7% of the candidature.
Maths Extension 1 - Draw.
Your marks are the same. No issue.
Of those four directly comparable courses, you come out on top overall. But you probably already knew that.
It's somewhat more difficult to compare the remaining courses. It's not impossible... however, we have to use scaled marks to do it.
Chemistry (course loading: 6.5)
Your scaled mark ~ 44.7/50
This places you at the 94th percentile.
Physics (course loading: 5.3)
Your scaled mark ~ 43.8/50
This places you at the 93rd percentile.
Economics (course loading: 6.0)
His scaled mark ~ 45.6/50
This places him at the 96th percentile.
Industrial Technology (course loading: -8.1)
His scaled mark ~ 38.0/50
This places him at the 99th percentile.
Perhaps I didn't need to go through all of that, but I like to have a clear 'big picture' of what is going on. It's clear now what you're asking... but not entirely clear what you're disputing. How can a student scoring in the top 1% for a course end up with such a (comparatively) poor scaled mark?
The appropriate answer would involve another explanation of the underlying mechanisms of the scaling algorithms. That's already been given a few times in this thread... doesn't seem to be what you're after. In fact I'm not exactly sure what you're after.
Let's try and make things clearer (again):
Fact: Industrial Technology had a scaled mean of 16.9.
This means that the overall academic ability of all students who took Industrial Technology was low. Overall academic ability is measured from the performance of each student
in all the courses they took. It's analogous to calculating the average academic ability for every student taking IT, and then averaging all of those averages to give an overall course average. This is how the scaled mean is determined, and hence determines whether a course is scaled up or down.
The rationale: In a course that is taken by students with a high overall academic ability, it is
harder for an average student to attain a high ranking. In a course that is taken by students with a low overall academic ability (such as IT), it is
easier for an average student to attain a high ranking. Each of these cases must be compensated for - the first course will be scaled up whilst the second will be scaled down. This balances marks across all courses.
Which part of this are you disputing? Do you disagree with the methods used to calculate scaled means? Or do you think Industrial Technology actually has a very able candidature?
I'm assuming that, even with everything I've written, you won't be satisfied after this post. I urge you to tell us exactly what you have a problem with. Pinpoint it. Describe the flaw. Make it blatantly obvious.
Otherwise we could go on forever.
.. Most of these marks were Band 5.
