Scaling (1 Viewer)

[googy_1985]

Hi,
After taking months to work out the whole scaling and adjusting marks for the HSC and UAI - I was wondering what do Unis do???


I am doing a Commerce/Economics degree in ACT - University of Canberra.. Do they usually fix the mean to a certain mark and scale around that etc?? or is it up to the individual lecturer?

 

[Lazarus]

They shape it to a normal (bell curve) distribution - fixed percentage of students in each grade range. The exact percentages vary between faculties and universities.

 

[Lazarus]

Originally posted by Cyph
Are you talking about a bell curve where the median mark is 65?

Not necessarily - as I said, the exact parameters vary. The term 'bell curve' is simply used to describe the shape of the distribution of marks. Generally, the bulk of the student body will be allocated marks around the pass/credit range, and the tail ends of the distribution will thin out towards the high distinction and low fail regions.

 

[Minai]

I'm unsure, but I think this doesn't necessarily happen in all subjects...I heard my lecturer saying that in ACCT1501: Accounting & Financial Management 1A @ UNSW, the mark u get is the mark u get basically (not exactly, because of scaling, but its not fit around a bell curve). Again, unsure if he's right on this..

 

[Lazarus]

It's possible. From what I understand, each faculty has their own little policy regarding it.

If I had to try and show how my explanation fits your example... I would hesitantly suggest that your exams and assessments might be marked with a bell curve in mind, so that by the end of the semester all of the marks already form the required distribution. I think the Faculty of Law does something similar to that.

But it's possible that not all subjects are normalised. Your head lecturer would know.

 

[kini mini]

Originally posted by Lazarus
It's possible. From what I understand, each faculty has their own little policy regarding it.

If I had to try and show how my explanation fits your example... I would hesitantly suggest that your exams and assessments might be marked with a bell curve in mind, so that by the end of the semester all of the marks already form the required distribution. I think the Faculty of Law does something similar to that.

But it's possible that not all subjects are normalised. Your head lecturer would know.

What Rachel said after Damjanovic seems to fit your explanation about how things work in law .

 

[Lazarus]

Originally posted by Cyph
Anyway, why isn't the median mark 65? Just something I remember my stats tutor mentioning the other day, but now I think about it, the median mark should be closer to 50, if not 50?

The 'median' is the point such that at least 50% of the statistics lie above it and at least 50% of the statistics lie below it. In a symmetrical distribution, it should be approximately the same as the mean; a median that is higher than the mean will indicate that the distribution is left-skewed (i.e. the bulk of the statistics are at the upper end). And one that is lower will indicate a right-skewed distribution.

A median mark of 50 would mean that 50% of students achieved marks above this (passed) and 50% were awarded marks below it (failed). The fail rate for most courses isn't quite that high.

As a sidenote, the old BOS bell-curve distribution used a median around 65 and a mean of 60. This meant that 1-2% of students received marks above 90, 20% received marks above 70 and 80% received marks above 50. 1% of students (at most) received marks less than 30.

I think that, generally, where scaling to a distribution does occur in a university course, it would be adjusted subjectively by the lecturer, and a fixed median etc may not necessarily be used every time.

 

[orangeguy]

i know scaling defers from different unis, but here at macq, in the economic and financial divison, my lecturer told me that he does not have to set a certain amount of people to fail. i.e. everyone can pass...and thus the bell curve does not exist. he commented that "the top certain percentage of people get HD etc.." does not apply.