Why are results scaled?

Scaling ensures that it is possible for students to attain a high ATAR regardless of the combination of subjects they undertake

The ATAR was created so that tertiary institutions could make fair comparisons between students.

THERE are hundreds of VCE and VCE VET subjects available, which means there are millions of possible VCE study programs that Year 12 students could select.

The ATAR was created so that tertiary institutions could make fair comparisons between students who have chosen any one of these different combinations. The ATAR is calculated based on Scaled Study Scores to ensure that no student is advantaged or disadvantaged by their choice of subjects.

To understand why scaling is necessary for a fair comparison, we need to start at the beginning. All student assessment in the VCE is administered by the Victorian Curriculum and Assessment Authority (VCAA). The VCAA provides a Study Score for each Unit 3 & 4 study, based on the marks a student receives for each graded assessment in that study. The Study Scores for all studies are reported on a scale of 0 to 50 with an average score of 30.

Despite its name, the Study Score is not actually a score out of 50. It is a ranking or relative position which shows a student’s performance compared with all other students who took that study in that year. A student with a Study Score of 30 is in the middle of the cohort, or has performed better than about half of all students who took that study in that year. A student with a Study Score of 40 has performed better than about 91% of all students who took that study in that year.

What this means is that the middle student in every study will have a Study Score of 30, regardless of how strong the other students were in the study and how difficult it was to achieve that middle ranking.

VTAC’s role is to provide a way of ranking students that is fair, regardless of the studies they have taken. To do this, we look at the strength of competition in each study. This is measured by looking at the performance of students in all of their other VCE studies.

Where the student competition in a study is higher, Study Scores have to be adjusted upwards; otherwise students doing that study would be unfairly disadvantaged.

Similarly, in a study where the student competition is lower, the Study Scores have to be adjusted downwards; otherwise students doing that study would be unfairly advantaged.

Scaling ensures that it is possible for students to attain a high ATAR regardless of the combination of studies they undertake. We complete this process afresh every year, and it is all based on mathematics. Scaling is all about the strength of the competition in that year, not about how hard we think a certain subject is.

This is not always well understood. Many people believe that to achieve their best possible ATAR, they need to choose studies which are scaled up. This is not true, and may even work against them.

If a student chooses a study that they are not very good at simply because it will be scaled up, the Study Score they receive will be a lot lower than what they would expect in a study they are good at and that interests them.

Yes, the score will be scaled up, but from a lower Study Score. It is unlikely that the VTAC Scaled Study Score would be any higher than if they had chosen a more suitable study, even one that is scaled down.

The way to ensure that you achieve the best possible ATAR is to choose studies according to what interests you, what you are good at, and what studies you need to meet prerequisites for future study.

The calculation of the ATAR is a detailed process, but it is the fairest system developed by experts which allows students to undertake the studies they want and enables tertiary institutions to compare students who have completed different combinations of VCE studies.

The use of the ATAR guarantees that all studies are treated equally and provides students with a common score for tertiary selection across Australia.