ATAR Notes: Forum

VCE Stuff => Victorian Technical Score Discussion => Topic started by: dankfrank420 on July 25, 2014, 06:33:11 pm

Title: Is SAC scaling constant?
Post by: dankfrank420 on July 25, 2014, 06:33:11 pm
The GA1 average for lasts year's Biology cohort was 72. This scaled to an 87, an increase of 15 marks.

Does this increase of 15 hold true? So if someone gets a GA1 of 80 would this also scale to 95?
Title: Re: Is SAC scaling constant?
Post by: Scooby on July 25, 2014, 06:51:08 pm
The GA1 average for lasts year's Biology cohort was 72. This scaled to an 87, an increase of 15 marks.

Does this increase of 15 hold true? So if someone gets a GA1 of 80 would this also scale to 95?

Nope, not at all. Generally the further away you move from the median, the less effect moderation has (it's not as simple as just adding or taking "X" from everyone's score)
Title: Re: Is SAC scaling constant?
Post by: dankfrank420 on July 25, 2014, 06:59:30 pm
Thanks for your reply.

From your experience, is the change in moderation that drastic? Considering the increase in the OP, do you think that a score of 80 be enough to scale to over 90?
Title: Re: Is SAC scaling constant?
Post by: Scooby on July 25, 2014, 07:14:17 pm
Thanks for your reply.

From your experience, is the change in moderation that drastic? Considering the increase in the OP, do you think that a score of 80 be enough to scale to over 90?

Yeah, definitely. It can be even more drastic than that. Even something like +30 isn't out of the question
Title: Re: Is SAC scaling constant?
Post by: dankfrank420 on July 25, 2014, 07:41:19 pm
Sorry, didn't explain my second question enough.

When I say the change in moderation, I mean that since 72 got scaled up 15 points, would 80 get scaled up 5, 10, 12 points?
Title: Re: Is SAC scaling constant?
Post by: spectroscopy on July 25, 2014, 07:53:17 pm
The GA1 average for lasts year's Biology cohort was 72. This scaled to an 87, an increase of 15 marks.

Does this increase of 15 hold true? So if someone gets a GA1 of 80 would this also scale to 95?
no it doesnt, the sac score scales to whatever the exam score of the correlating rank was
eg; if 72 was the 15th highest sac score, that means 87 was the 15th highest exam score
Title: Re: Is SAC scaling constant?
Post by: Scooby on July 25, 2014, 07:59:04 pm
Sorry, didn't explain my second question enough.

When I say the change in moderation, I mean that since 72 got scaled up 15 points, would 80 get scaled up 5, 10, 12 points?

There's no way of determining that. "If you're ranked X you'll get the X highest exam score as your SAC score" is a good way of thinking about it, but it's a bit of an oversimplification of what really goes on. You can definitely get a moderated SAC score of 100% without anyone in your cohort getting a perfect exam score
Title: Re: Is SAC scaling constant?
Post by: nerdmmb on July 25, 2014, 08:21:45 pm
Whaaa?

If someone is ranked 4 with an 80 for Unit 3 and manages to average >90 in their Unit 4 sacs and also gets >90 on their exam,
How likely is it that they'll get a study score of 46+?

Or as Scooby mentioned, if someone is ranked 4 or 5, do they get the 4th exam score?

Geez, VCAA's marking scheme is SOO unfair :(
Title: Re: Is SAC scaling constant?
Post by: keltingmeith on July 25, 2014, 11:16:49 pm
Whaaa?

If someone is ranked 4 with an 80 for Unit 3 and manages to average >90 in their Unit 4 sacs and also gets >90 on their exam,
How likely is it that they'll get a study score of 46+?

Depends on the subject, but potentially yes.

Or as Scooby mentioned, if someone is ranked 4 or 5, do they get the 4th exam score?

The difference between the two is so miniscule, it wouldn't matter whether they were given 4 or 5.

Geez, VCAA's marking scheme is SOO unfair :(

It's actually a very good system as to what they do, it's just how they do it that's unfair. As Scooby said, what was mentioned is a massive oversimplification. The only way to sort of understand VCAA's scaling between schools and subjects is to have a good understanding of normal distributions.
Title: Re: Is SAC scaling constant?
Post by: nerdmmb on July 25, 2014, 11:28:26 pm
So if a student scored the highest exam score in their school, would that score be given to the top ranked student?

:S
Title: Re: Is SAC scaling constant?
Post by: Scooby on July 26, 2014, 12:17:36 am
So if a student scored the highest exam score in their school, would that score be given to the top ranked student?

:S

Everyone keeps their exam score as their own exam score

If you're ranked X, you receive the X highest exam score as your SAC score. Say, if you're ranked 4th, you'll receive the 4th highest exam score as your SAC score. You'll keep your own exam score of course. But yeah, thinking about it that way is well and truly oversimplifying it (so there's not really much point thinking about it that way)