ATAR/Scaling Questions

[RuiAce]

What? So basically all that matters is the HSC external exam? What's the point of the school assessment and external assessment then if there is an equal weighting of 50% for each? I heard this one girl at ruse came third internally but smashed externals and came first in the state for bio. Was this because her internals were completely redundant or what?

If you're a cohort of 1 student, ultimately there IS no point.

Whereas if you're in a cohort of at least 3, the raw marks still don't matter. It is the relative mark differences as Jamon would've said that matters.

I.e. Cohort one has marks 90, 80, 70 internally, whereas cohort two has marks 90, 75, 70. Moderation will impact DIFFERENTLY

Cohort three has marks 90, 80, 70 internally, whereas cohort four has marks 80, 70, 60. Moderation will basically do the SAME thing to BOTH cohorts

[jamonwindeyer]

What? So basically all that matters is the HSC external exam? What's the point of the school assessment and external assessment then if there is an equal weighting of 50% for each? I heard this one girl at ruse came third internally but smashed externals and came first in the state for bio. Was this because her internals were completely redundant or what?

Internal RANK matters, as does relative placement within the cohort. But the value of the mark itself does not. The purpose of this is that schools will assess differently, but as long as all students in the same school get the same tasks, the ranks can be trusted, even if the marks can't be 🏻 I suppose we do internal assessments because basing absolutely everything on a single exam would be really mean, so they give you a chance to influence it

[conic curve]

Internal RANK matters, as does relative placement within the cohort. But the value of the mark itself does not. The purpose of this is that schools will assess differently, but as long as all students in the same school get the same tasks, the ranks can be trusted, even if the marks can't be 🏻 I suppose we do internal assessments because basing absolutely everything on a single exam would be really mean, so they give you a chance to influence it

Would there be a moderation effect on a cohort with only 2 students?

So if your internal average mark was like 60 and your external mark was 95 (and you were first in the cohort and the exams were more difficult than the HSC, the BOSTES would do the average of the two exams and scale it up to like 90 (I'm assuming)

Wouldn't the same thing apply in a cohort of 1-2 students?

[RuiAce]

Would there be a moderation effect on a cohort with only 2 students?

So if your internal average mark was like 60 and your external mark was 95 (and you were first in the cohort and the exams were more difficult than the HSC, the BOSTES would do the average of the two exams and scale it up to like 90 (I'm assuming)

Wouldn't the same thing apply in a cohort of 1-2 students?

I'm fairly positive a cohort of 2 works just like a cohort of 1 yes.

[jakesilove]

Would there be a moderation effect on a cohort with only 2 students?

So if your internal average mark was like 60 and your external mark was 95 (and you were first in the cohort and the exams were more difficult than the HSC, the BOSTES would do the average of the two exams and scale it up to like 90 (I'm assuming)

Wouldn't the same thing apply in a cohort of 1-2 students?

Student A get 60 internally, 90 externally
Student B gets 55 internally, 83 externally

Very likely, as an overall mark, student A will get 90 for internal and 90 for external, whilst student B will get 83 for internal and 83 for external (with some very minor modification).

Student A gets 60 internally, 83 externally
Student B gets 55 internally, 90 externally

The marks will then become more difficult to quantify, but Student A will receive a mark of 83 for their external mark, and slightly below 90 for their internal mark. Conversely, Student B will get 90 for their external mark, but slightly above 83 for their internal mark. You take your rank, find that rank in the cohort for the external exam, and that is approximately your internal mark. It works exactly the same for a cohort of 1, 2, 80 or 140.

[EmileeSmith]

ohh this makes way more sense, thank you!

[fizzy.123]

Will I be able to get a 90+ atar with the following marks?

English Adv: 78/100 - Rank: 5/23
Maths: 83/100 - Rank: 3/9
Business Studies: 84/100 - Rank 2/17
PDHPE: 89/100 - Rank: 3/17
Society & culture: 88/100 - Rank: 3/19

[jakesilove]

Will I be able to get a 90+ atar with the following marks?

English Adv: 78/100 - Rank: 5/23
Maths: 83/100 - Rank: 3/9
Business Studies: 84/100 - Rank 2/17
PDHPE: 89/100 - Rank: 3/17
Society & culture: 88/100 - Rank: 3/19

Hey! Whilst it is absolutely impossible to figure out what mark you're going to get, as it's very much dependent on your HSC scores and how difficult your assessments have been up until now, I think that your rankings indicate you can absolutely get a 90+ Atar. Actually, it is definitely possible; if you put in the hard work between now and the HSC, a 90+ is definitely achievable! Keep up the study and you'll get the marks you want

[RuiAce]

Will I be able to get a 90+ atar with the following marks?

English Adv: 78/100 - Rank: 5/23
Maths: 83/100 - Rank: 3/9
Business Studies: 84/100 - Rank 2/17
PDHPE: 89/100 - Rank: 3/17
Society & culture: 88/100 - Rank: 3/19

Whenever I see this type of post, I always flat out say yes.

Because fact is if you gun the final exams, these aren't going to matter. Regardless of what courses you chose.

[EmileeSmith]

does anyone know where I can find the subject scaling website ?

[jamonwindeyer]

does anyone know where I can find the subject scaling website ?

Hey! There isn't a website that explains it or gives you the exact numbers, per say, but this report contains all the information you need. It's a massive read, but I've synthesised important bits in the article that I linked in the first post of this thread, and there are tables at the end with some nice stats

[RuiAce]

does anyone know where I can find the subject scaling website ?

As Jamon mentioned, there is nothing that will ever give you the exact scaling algorithm. The parameters need to be changed every year due to each year's exam being different, and the data being different as well.

Especially since you are talking about 'scaling', which is what UAC does to generate your ATAR.

[conic curve]

Just in case anyone's interested, I enquired with the UAC about what happens when you do a course one to one with a tutor and this is what they said

Spoiler

"The scaling process is designed to encourage you to take courses for which you are best suited and which best prepare you for your future studies. The underlying principle is that you should be neither advantaged nor disadvantaged by choosing one HSC course over another. The scaling algorithm estimates what your marks would have been if all courses had been studied by all students and all courses had the same mark distribution.

With the exception of English, which is compulsory, you are free to choose your courses of study. Consequently, individual course candidatures vary in size and nature, and there are many different enrolment patterns. In 2015, there were more than 27,000 different enrolment patterns for ATAR-eligible students; of these, almost 20,000 patterns were taken by only one student.

Given the choice available, your rank in different courses will not necessarily have the same meaning. A good rank is more difficult to obtain when you are competing against students of high academic ability. Because of the lack of comparability, your raw marks are scaled before they are added to give the aggregates from which ATARs are determined.


Scaling modifies the mean, the standard deviation and the maximum mark in each course. Adjustments are then made to the marks of individual students to produce scaled marks. Although scaled marks are generally different from the raw marks from which they are derived, the ranking of students within a course is not changed.

Once the raw marks have been scaled, aggregates are calculated for ATAR-eligible students.

Percentiles, which indicate the ranking of students with respect to other ATAR-eligible students, are then determined on the basis of the aggregate of scaled marks.

The penultimate step is to determine what the percentiles would have been if all students in their Year 7 cohort completed Year 12 and were eligible for an ATAR. The last step is to truncate these percentiles at intervals of 0.05, commencing at 99.95. These are the ATARs.

Each ATAR corresponds to a range of aggregates.

The scaling process, which does not assume that one course is intrinsically more difficult than another or that the quality of the course candidature is always the same, is carried out afresh each year. All students who complete at least one ATAR course in a given year are included in the scaling process for that year."

Moderator Edit: Added Spoiler
So basically they just scale your marks up

[RuiAce]

I am thoroughly amazed by the amount of effort they put in to give you that reply

[conic curve]

I am thoroughly amazed by the amount of effort they put in to give you that reply

Ok. They did it all this morning

DO you want to see the picture of me emailing them?