How ATAR Scaling Works in NSW
The ATAR (Australian Tertiary Admission Rank) is not calculated directly from raw HSC marks. The process involves two stages. First, moderation: within each school, NESA adjusts students' internal assessment marks so the school assessment distribution matches the external HSC exam distribution for that cohort. This prevents schools from inflating internal marks. Second, scaling: the Universities Admissions Centre (UAC) converts each student's HSC marks to a scaled mark based on the performance of the entire candidature in that subject. Subjects with a high-performing cohort (many academically strong students choose them) scale higher — historically, Mathematics Extension 2, Chemistry, Physics, and Economics have scaled well above their raw marks, while some humanities and vocational subjects may scale below. The scaling system means a mark of 85 in Chemistry may yield a higher ATAR contribution than 95 in a lower-scaling subject. Crucially, the scaled mark reflects relative performance within the subject's candidature — the absolute mark matters less than where you rank among all students who sat that subject. NESA publishes historical scaling data via UAC reports, which students should consult when planning their subject selection.