QCE System Explained – ATARs, Assessments, Polyranks, Inter-Subject Scaling & More!By ATAR Notes in QCE
27th of September 2019
Looking for more info and free resources for QCE? Check out these resources!
Perhaps the most daunting element of the new QCE system is the concept of the ATAR – or, less colloquially, the Australian Tertiary Admission Rank. Broadly, the ATAR can be seen as “the thing that gets you into university”, as it is one metric that tertiary institutions use to determine entrance requirements. But at a deeper level, what is the ATAR, really? How is it calculated? And how will processes like inter-subject scaling affect you?
The purpose of this article is to make these concepts a little clearer. Importantly, it is not to help you “game the system” or get any meaningful advantage, as there is really no system to game. Where knowing this information can come in handy is reducing stress, arming you with knowledge to avoid reading into misconceptions and rhetoric, and providing comfort that, at the end of the day, processes are in place to ensure fairness.
Ultimately, your best bet for doing well through your QCE studies is to choose subjects you like, be consistent, and work on the things you can control. But if you have any questions about the technical side of QCE or the ATAR, feel free to ask them in our dedicated sections below!
What is the ATAR?
The ATAR is not a score – at least, not in the regular sense. Instead, it is a rank.
If you achieve an ATAR of 75.00, for example, that does not mean that you averaged 75% across the year on your assessments. It doesn’t mean that you scored 75% on your end-of-year exam. What is means is that, based on your internal assessment and exam performance, you outperformed 75% of your competition.
The highest possible ATAR is 99.95. You can’t get an ATAR of 100, because that would mean you outperformed 100% of your cohort, including yourself! From there, ATARs descend in increments of 0.05 – so 99.90, 99.85, 99.80, 99.75, and so on, until we reach “less than 30”.
So how is your ATAR actually determined? Let’s work backward, starting with something called the Tertiary Entrance Aggregate (we’ll just refer to this as the aggregate).
What is the aggregate?
You can picture the aggregate sort of as a “total score” of QCE performance. It’s the combination of your five best scaled QCE Units 3&4 subject results (even though it’s now compulsory to study an English subject, it does not need to be included in these top five subjects). What this means is that, even though it is possible to complete more than five QCE subjects, a maximum of five will count toward your ATAR.
This also means that, to be eligible for an ATAR, you need to complete at least five subjects including an English subject. There are some rules that govern this, which you can read about more here on QTAC’s website. There are also different options – you can study, for example, a combination of General subjects, Applied subjects, and VET qualifications.
Once every eligible student has an aggregate, they are ranked from highest to lowest, and the aggregate is then converted to a percentile ranking – the ATAR.
So we know that the ATAR is a percentile ranking, and that it’s based on the aggregate. We also know that the aggregate is based on a combination of a student’s top five subject scores. But how are those subject scores calculated?
How are QCE subject scores calculated?
Like the ATAR, averaging 75% across all of your assessments for a subject does not guarantee a subject score of 75 – there are more factors at play.
Put simply, subject scores for General QCE subjects* are based on:
- Three internal assessments (administered by the school); and
- One external assessment (consistent for all students across the state).
As such, both internal and external assessments matter, and you should try your hardest on both! But you might have noticed something else: if at least some of your subject scores depend on internal assessments, how can we ensure that students aren’t unfairly affected by different assessments administered by schools?
That’s a great question, but don’t stress: processes called endorsement and confirmation exist precisely for this reason, so you can be confident in the knowledge that you won’t be “punished” or “rewarded” based on which school you attend.
But there’s one other issue, and it’s a really big one: students across Queensland have a huge number of QCE subjects to choose from, and many of these are fundamentally different. Achievement in, say, Chemistry, is very difficult to compare against achievement in, say, Physical Education. Subsequently, we need some way to counter the fact that different students will study different subjects. The answer? Inter-subject scaling.
* For Applied subjects, there are four internal assessments, and no external assessments.
What is inter-subject scaling in QCE?
If one student achieved an 82 in Mathematical Methods and another achieved a 64, it seems straightforward to say that the first student outperformed the second. It’s not this easy, though, when comparing across subjects. Can we say that a 90 in Geography is better than an 88 in Specialist Maths? What if we tried to compare Geography and Biology?
The idea of inter-subject scaling is to allow easy comparison of results not only within QCE subjects, but across them. If scaling didn’t exist, students could, theoretically, try to “game” the system by studying exclusively what they perceive to be easy subjects in order to maximise their ATAR. Having inter-subject scaling means that students can simply choose the subjects they’re most interested in without having to worry about any adverse impact on their results.
It’s very important to understand that scaling does not change your level of achievement – it simply alters the scale of reporting. Let’s say we were comparing the weights of two people: Person A (60 kilograms) and Person B (100 pounds). We can’t just say that Person B weighs more because 100 is a larger number than 60 – the scales are completely different! To accurately compare, we need to convert the measurements onto the same scale. This does not at all change the actual weight of either Person A or Person B.
Inter-subject scaling works in a similar way. Let’s take a look at it a bit more closely.
How does inter-subject scaling work?
Let’s assume you’re studying five General QCE subjects. First, you will receive a “raw subject score” for each of your subjects, based on the three internal and one external assessment. These are then converted to estimated scaled marks, based on how your performance compared to other QCE students studying each subject. For example, if your raw mark of 78 in Chemistry placed you at the 84th percentile of students studying Chemistry, 84 will become your estimated scaled mark.
But we can do more than this, based on relative competitiveness of each QCE subject. This is necessary because different subjects may have very different cohorts. For example, imagine coming third in a race against professional sprinters, and your friend coming third in a race against toddlers, and people saying that the achievement was equal. Ludicrous! Looking at competitiveness of each subject gives us a better indication of actual performance.
To do this, we use something called a “polyrank”. The polyrank is a student’s average mark (using estimated scaled scores) across their subjects, based on their top five subjects. Something like this:
You might notice that, in this situation, Student A and Student B both received a raw mark of 94 in General Maths. To indicate how competitive that subject was overall, we can now take every single QCE student who received a 94 in General Maths, and find the average polyrank of those students. This average polyrank approximately becomes the new estimated scaled rank, and the process is repeated for every single mark across every single subject. This might lead to something like:
Great – we now have a new round of scaled subject scores, based on competitiveness of each of those subjects! But you might notice that we now also have new polyranks. As such, we can do the same process again, and again, and again. This is called an “iterative” process, where calculation of scaled scores affects polyranks, which affects scaled scores, which affects polyranks, and so on.
This repeats until the estimated scaled scores flatten out and stabilise. It is these eventual, stabilised scaled scores that contribute to the aggregate and, ultimately, the ATAR.
Key takeaways of the technical QCE system
If nothing else, there are some key things you should take from this article:
1. Inter-subject scaling does not “reward” or “punish”
In fact, it has been specifically designed to make QCE subjects a level playing field. High scaling is negated by strong competition; lower scaling is negated by weaker competition. Which means:
2. You shouldn’t choose subjects based on scaling
Instead, you should choose subjects you enjoy, that you’re good at, and that you need as pre-requisites. You are much more likely to score highly when studying something you’re interested in or passionate about.
3. There’s no real way to “game” the system
And it’s a waste of time to try! The QCE system has been developed by experts, who absolutely know what they’re doing.
4. Knowing this isn’t the end of the world!
At the end of the day, will having an intricate understanding of the QCE system guarantee a high ATAR? Absolutely not. Do you need to know the ins and outs of scaling in order to do well? Absolutely not.
As we said earlier, having this knowledge can help reduce stress, and give you a better understanding of the system you’re a part of. But persistence, dedication, and effective study techniques are the things that will ultimately help you most, and, luckily, also the things you have control over! These are the things you should focus on. You can start by checking out some of these free QCE resources!
That’s cool – some of this info has been pretty dense! Feel free to ask any follow-up questions you have here, on our dedicated section of the ATAR Notes Forums:
NOTE: QTAC does not endorse or have any involvement in any material appearing on this website. Material presented is the assumption of the author based on publicly available documents and resources.