Category: HSC Scaling

Scaling of HSC Maths

In terms of scaling, choosing HSC maths is generally a positive step towards maximising your UAI / ATAR. Historically, mathematics of all levels have scaled very high relative to other HSC subjects, and this trend has continued into current years. For example, if we look at the latest scaling statistics submitted by the UAC, then we could see some remarkable changes like-

Scaled mean of HSC maths of all levels for the year 2008 were HSC Maths (2 unit) – 30.4, HSC Mathematics Extension 1 – 40.0 and HSC Mathematics Extension 2 – 44.5 respectively.

Scaled mean of HSC maths of all levels for the year 2007 were HSC Maths (2 unit) – 30.5, HSC Mathematics Extension 1 – 39.6 and HSC Mathematics Extension 2 – 43.7 respectively.

The HSC mean mark of HSC maths of all levels were HSC Maths (2 unit) – 38, HSC Mathematics Extension 1 – 40 and HSC Mathematics Extension 2 – 41.8.

From these statistics, we see that all levels of maths have actually increased in scaled mean, with the exception of 2 unit maths. In particular, Maths Extension 2 has increased from a scaled mean of 43.7 to 44.5. This has placed Extension 2 as the second highest scaled subject available to students (first being Classical Greek Extension, at 45.2).

Apart from this, Scaled mean of HSC English Advanced for the year 2008 and 2007 was 31.3 and 31.2 respectively. Moreover, its HSC mean mark was 39.7. Basically, in terms of the benefit to a student’s ATAR, an average raw mark in Maths Extension 2 is equivalent to scoring in the top 2-3% for HSC Physics, Chemistry, or English Advanced. If you score the average raw mark for Maths Extension 2, the number of scaled marks added to your aggregate mark (which is used to calculate your rank position and ultimately ATAR) is the same as if you scored in the 97th-98th percentile in some other relatively high scaling subjects, like HSC Chemistry or Physics. These numbers illustrate the huge scaling effect of Extension 2 maths.

(To find out more about how the HSC scaling process works, read our comprehensive article on the HSC scaling process).

Similarly, Maths Extension 1 also benefits from a large positive scaling effect. In 2008, its scaled mean of 40.0 means that if you scored the average raw mark in Maths Extension 1, the number of marks added to your aggregate mark is the same as if you scored in the top 15% for HSC Chemistry, or Physics, or the top 10% in Biology.

ATAR to Replace All UAI's

The UAC announced earlier this month that the UAI system will be replaced by the ATAR (Australian Tertiary Admissions Rank). The conversion of UAI to ATAR aligns NSW’s system of measuring HSC performance for the purpose of university admissions to that of other states. The ATAR will replace all UAI’s, starting with the year 12 students in 2009, and will be a rank-based score out of 99.95 (instead of 100.00).

How will the ATAR affect me?uai-to-atar-score1 The ATAR is a similar (but not identical) rank-based scale used to differentiate student performance for the purpose of university admissions. Like the UAI, the ATAR is a rank-based index, meaning the same rules of HSC scaling would apply under the ATAR.

Students should remember that just like under the UAI system, it is your rank relative to other HSC students which determine what ATAR / UAI you will receive. That is, based on your aggregate mark (out of 500), your percentile position will be calculated, and this will be directly converted into an ATAR. As a result, the number will change when converting from UAI to ATAR, however your rank remains the same. As a result, university ATAR cut-offs for all courses will be converted to match the previous equivalent rank cut-off.

For example, say Bachelor of Commerce at UNSW has a UAI cut-off of 90.00. Say this translates to a rank cut-off at the 8,800th student from the top rank. The ATAR cut-off would be adjusted to match the rank, and not be converted according to some arbitrary process. E.g. according to UAC’s published UAI to ATAR conversion table, a UAI of 90 converts to an ATAR of 90.80.

Converting from UAI to ATAR score

Read UAC’s full conversion table here.

Because both the UAI and the ATAR are rank-based scores, they are directly comparable to previous years’ UAI scores. So if you have an older brother or sister and want to best them in the HSC, the implementation of the ATAR system won’t affect that! Notice that the highest attainable ATAR is 99.95 (instead of a UAI of 100). As a result, UAI’s near 100 (above 99.7) are converted to a slightly lower ATAR score, and all UAI’s lower than 99.2 are converted to a slightly higher ATAR. For the vast majority of students, this makes their university entrance score look slightly better! However, again we remind you that your rank is not affected by these changes, and therefore the difference in numbers between the ATAR and UAI make no difference to you.

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