HSC Physics

A subject I wish was studied more

I find Physics interesting. I know far too little about it to say any more, but as it relates to the HSC, I have a few things to share. As with most things HSC, I have more pictures to show than words to write. So that’s probably good for everyone.

I like Physics teachers because they tell terrible, terrible jokes and make teachers of any other subject seem like genuinely funny people. It’s like how you should always be friends with a surfer, so you can feel good about your intellect.

Physics achievement, like other sciences in the HSC, has been on the move.

Here’s what band achievment and HSC candidatures in Physics have looked like since 2007.

14% of NSW HSC students studied Physics in 2007. By 2024 that had dropped to 11.1%. That’s a significant change. Band achievement in Biology hasn’t changed as much in Physics as it has in Biology in recent years. Since 2020, band4, 5 and 6 achievement has remained quite steady.

Here’s the distribution of HSC scores from Band 2 and up in Physics in 2024.

Scaling in Physics

Here’s what scaling in Physics has looked like since 2007.

In Physics Band 6 acheievment has remained relatively steady over recent years, but there’s been a pretty pronounced change in the implications of achievement at lower bands in the HSC. Each dot represents an HSC score from 0-100. Each dot is coloured by Band. Red scores are Band 1s, yellows are Bands 2 and 3, blues are bands 4 and 5 and pink dots on the right are Band 6 scores. The left most pink dot is the first Band 6 score, so an HSC score of 90. How far across to the right a dot is shows what that HSC score was worth to a student’s ATAR.

HSC scores of 90+ being pretty steady in terms of what they’re worth to student ATARs is in contrast to what’s been happening in Biology and Chemistry.

Band 6 scores in Physics are difficult to achieve. According to scaling, and my estimates, Band 6 scores in Physics are the second most difficult top band results to achieve in any 2 unit subject in the HSC, after Chemistry.

Physics and Chemistry used to scale similarly all the way through. That’s changed in recent years. They’re still similar, to be sure, but they’re not so much like twins anymore.

Here’s how all Science subjects scaled in 2024.

At Bands 1, 2 and 3, Physics and Chemistry are basically identical. But from high Band 4 scores, Chemistry starts to pull away and by Band 6, although the gap is small, at that level of achievement small gaps are significant as they’re so close to the ceiling anyway.

Here are just those top band scores zoomed in a little.

Although in lower bands of achievement, Physics and Chemistry scale similarly. By the time we’re up to Band 6 achievement, Physics scales more similarly to Biology, even if not in the proportion of students who reach Band 6 level.

And here’s a simplified look at all band achievement in Physics in 2024.

Here’s what Physics scaling looked like in 2024, compared to HSC scores.

This comparison is a big reason Physics has such a stellar repuration for scaling. The straight line is HSC scores. The blue dots off the green line are those HSC scores as ATAR contributions. Sometimes people talk about when subjects scale up and down. This shows what they mean by that. But it’s not a good way to think about the HSC. Where a blue dot is in relation to the straight line doesn’t represent positive or negative contributions to ATARs. It’s just that HSC scores are linear, but how they scale is not.

Physics, compared to HSC scores, is a high scaling subject. That just means that it’s difficult to achieve those HSC scores in Physics. And when an HSC score in Physics is worth more to a student’s ATAR than an equivalent HSC score in another subject, that’s because UAC is estimating that the same HSC score in Physics is more difficult to achieve than in other subjects.

When we look at Physics scaling from 2023 to 2024, the lower bands became more difficult to achieve and higher HSC scores remained steady.

Here’s what all HSC scores meant as ATAR contributions, by my estimations, in 2024.

And here’s the same thing, but using ATAR contributions as a starting point rather than HSC scores. So the same as the chart above, but in reverse. This shows the lowest HSC scores required in 2024 to achieve different ATAR contributions.

Physics - Difficult and Worth It

I worry that more students than ever before are opting for perceived easy things over the valuable struggle of doing difficult things.

Physics is difficult. It’s also a great subject and wrestling with it makes you smarter. I want students who are interested and ready for Physics to take it. Maybe the reduced numbers is a good thing. But I worry it’s not and I don’t want it if it’s not.