What is HSC scaling?

What is scaling?
Scaling is the process of taking HSC marks and standardising them across different subjects. Scaling is done by the University Admissions Centre (UAC) and allows results in different subjects to be compared with one another so as not to disadvantage students based on their subject selections or school’s system. Scaling works by standardising HSC marks so students who complete different courses can be ranked against each other for the purposes of creating an Australian Tertiary Admissions Ranking (ATAR). This involves looking at how difficult the subject is and providing a scale. It allows UAC to compare students who do Standard English with Students who do Advanced English or we can compare a student who received a 90 in Mathematics with another student who received a 90 in Legal Studies. Without scaling, this comparison would make it difficult to determine the relative levels of student achievement.
What does high scaling v low scaling subjects mean?
The level of scaling that is performed leads to some subjects such as Mathematics Extension 2 being known as high scaling. But what does this mean? Historically, students who do Mathematics Extension 2 receive higher marks in other ‘difficult’ subjects like English Advanced and that Mathematics Extension 2 is also considered ‘difficult subject’ with higher performing students in the cohort. That is, in the algorithm used to create an ATAR, some subjects will have a higher weighted contribution than other subjects as the exams are written at a higher level, and they are harder to achieve high scores in. They are then scaled up.
Should you avoid doing ‘lower’ scaling subjects?
A student should select the subjects they like most and are likely to perform best in. If a student is confident that they will do well in their chosen subjects, it is possible to achieve a high ATAR with any subject mix.
Is there an advantage of doing higher level subjects in English and Maths?
Yes, there can be. If one has the ability, one should do the highest level of these subjects that they are capable of. This is important for academic reasons. The best academic learning comes when students are challenged to grow. Therefore, taking a subject that they find challenging will help the student grow academically. If they do well in that subject there can be a scaling benefit in their favour. In terms of scaling – note the following: if a student scores in the 90th percentile for English Advanced they will receive a scaled mark of 41.5/50 per unit, whereas the same percentile in English Standard would mean they receive a scaled mark of only 31.8/50. Clearly students with the capability should choose English Advanced over English Standard for the academic challenge and the added benefit of a scaling advantage.
For more detailed look at scaling check out the University Admissions Centre website here.