With all the focus on HSC marks and ATAR at the end of year 12, you likely have some questions about how to understand these marks and even how they are calculated.

Defining HSC Marks and ATAR

Your HSC marks tell you about your performance. It is based on the average of your HSC examination and your school assessment mark. Your Australian Tertiary Admission Rank (ATAR) ranks you within your age group and State, based on performance across your Top 10 ATAR units of study.

The ATAR is a percentile ranking of a student’s overall academic achievement in the HSC and a performance measure that enables students who have completed different combinations of HSC courses to be compared with one another. The ATAR ranks students to help universities select applicants based on their academic performance overall.

Qualifying for an HSC

First, to qualify for an HSC, students must complete at least 12 units of preliminary courses and at least 10 units of HSC courses.

These HSC courses must include at least:

• 6 Units of Board Developed courses
• 2 Units of Board Developed English
• 3 HSC Board Developed/Endorsed Courses* of two-unit value or greater
• 4 Subjects

*Board Developed Courses are courses developed by the New South Wales Education Standards Authority (NESA).

ATAR eligibility

The ATAR rules, as established by Universities Admissions Centre (UAC), are slightly different to the HSC rules to ensure that students who intend to go on to university are well prepared for the demands of tertiary study. To be eligible for an ATAR in NSW, you must satisfactorily complete at least 10 units across courses that must include at least:

• 8 units from Category A courses
• 2 units of English
• 3 Board Developed courses of 2 units each
• 4 Subjects

Raw marks and scaling

While your HSC mark and ATAR are different measures of academic performance, the calculation of your ATAR is based on your HSC performance so that for each course a student completes, NESA provides the following marks:

• Raw examination mark
• Raw moderated school assessment
• Aligned examination mark
• Aligned moderated school assessment
• HSC mark

Raw HSC marks, rather than NESA’s reported HSC marks, are used in the scaling process. These marks are not reported to students, meaning students are unable to calculate their ATAR based on their HSC results. To help clarify how a student’s HSC marks are transformed to ATAR, we will discuss in this article:

1. Your HSC Results (NESA)
2. Scaled HSC Marks (UAC)
3. ATAR Percentile (UAC)

Our article on achieving a Band 6 also discusses scaling.

1. Your HSC Results

Your HSC results present a profile of your HSC achievement and provide the following marks for each course

• Aligned Examination Mark: indicates the standard reached by a student and their position within the performance band. For example, a mark of 61 means that, while the student has performed at a Performance Band 3 standard, their achievement is towards the bottom of this band.
• Aligned School Assessment Mark: to enable school assessments from different schools to be compared the school assessment marks submitted by each school are moderated using the raw examination marks gained by their students.
• HSC Mark: Your HSC mark is the average of your aligned examination mark and your aligned school assessment mark, which is based on how your school went in the actual HSC exams and where you are ranked in your school. The NSW Education Standards Authority (NESA) takes raw HSC marks and aligns them to performance bands to calculate HSC marks.
• Performance Band: For each HSC course, NESA develops standards—based on criteria such as the content, skills, concepts and principles of the course—in order to scale performance. Two-unit courses have six performance bands, while extension courses have four performance bands.

Once your HSC marks are determined by NESA, they are submitted to the UAC for conversion to scaled marks.

2. Scaled HSC Marks

The underlying principle of the ATAR scaling process is that a student should neither be advantaged nor disadvantaged by choosing one HSC course over another. It is designed to encourage students to take the courses for which they are best suited, and which best prepare them for their future.

The scaling model assumes that a student’s position in a course depends on the student’s developed ability in that course as well as the ‘strength of the competition’ as demonstrated by the overall academic attainment of the entire course candidature. A scaling algorithm is applied to raw HSC marks to estimate what students’ marks would have been if:

• all courses had been studied by all students
• all courses had the same distribution of marks

The scaling process is carried out afresh each year, and all students who complete at least one ATAR course in a given year are included in the scaling process for that year. Students who are accumulating courses towards their HSC have their scaled mark for each course calculated in the year that each course is completed.

Scaling first modifies the mean, the standard deviation (SD) 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. Since different scaling is applied to different HSC subjects, your ATAR will be affected by your subject choices.

3. Your ATAR is a Percentile Score

Once the raw HSC marks have been scaled, aggregate marks are calculated, students are ranked in order of their aggregate, and a percentile is assigned then truncated to the nearest 0.05 to provide your ATAR.

Aggregate marks are the sum of scaled marks in your ATAR courses. Each unit is worth 50 points, so the top ten units have a value of 500 points, and your total mark is referred to as an Aggregate. Students are then ranked in order of their aggregate, and a percentile is assigned to distribute students as evenly as possible over a 100-point scale.

Your percentile equates to the percentage of the ATAR cohort that received an aggregate mark less than or equal to your aggregate mark. The final stage is to truncate these percentiles to the nearest 0.05 to provide your ATAR – a number between 0 and 99.95. An ATAR of 80.00 means that you are in the top 20 percent of students for your age group (not your Year 12 group).

While ATARs are calculated for all ATAR-eligible students, only those students who indicate on their HSC entry forms that they wish to be notified of their ATAR will receive an ATAR Advice Notice from UAC. If you receive an ATAR between 0.00 and 30.00, your ATAR will be recorded as ‘30 or less’. If you haven’t met the requirements of the ATAR, your ATAR will be recorded as ‘not eligible’.

A large number of students will receive HSC marks between 70 and 80, so scoring closer to 80 can make a significant difference to your ATAR. Which is why, at Maths Words not Squiggles, we offer intensive HSC Exam Preparation Courses and Weekly Tutoring to prepare our Year 12 students for these final exams.

Need some help?

We understand that the HSC can be stressful for both parents and students alike. Not only do we offer specialised HSC Tutoring, as mentioned above, we also provide resources to help ease the minds of our students and parents. In our How to Prepare for the HSC article, MWNS teachers share their top tips on preparing for the HSC. Alternatively, if you are a parent looking for ways to make this difficult year more manageable and less stressful, read our HSC guide for Parents. Contact us here for any further information on our learning centres or any other queries.