Test taken: NSAA (Natural Sciences Admissions Assessment)
Number of interviews: 2
Time between interviews: around 1.5 hours
Length of interviews: 30-40 minutes
Online interview: Yes

For Physical Natural Sciences, we were given an option of Physics or Chemistry for the interview; I chose Chemistry but still got a mixture of the two, just Chemistry-biased. Interviews started off with a brief general chat before getting into the problems. The problems themselves got progressively more difficult, starting with more basic knowledge before they really started to push. The interviewers were lovely though, they really want to see you at your best so if you're unsure about anything then just ask!

A note about whiteboards - beforehand we were told we would be using Miro but this wasn't the case, instead, they expected you to annotate on the screen on the Zoom call. My best tip is to have two devices if that's possible for you, and join the call on the second device (muted and camera off, but let them know that's what you're doing). Also, remember to leave the call at the end on both devices! 

Firstly it's imperative you're on top of your A-level knowledge - don't learn new content you haven't covered yet but be firm on all your AS (Year 12) stuff.

As for more specific prep, I can't stress how great the Isaac Physics site is. There are so many problems on here that are exactly like what they'll give you in interview; I spent a lot of time on this site over year 12 and also into interview preparation! You'll also see a massive benefit in your A Level subjects from all the extra problem solving so you should 100% start doing some problems on the site if you haven't already!  Similarly to Isaac Physics, Olympiad Questions are good as it's helpful to practice conceptually challenging problems.

Try to get mock interviews with subject teachers where they just ask you some challenging questions about the subject. This is particularly useful for verbalising your thought process and practice to avoid the deadly phrase "I don't know". They're also very handy to prepare good answers to the standard questions like "Why do you want to study Natural Sciences at Cambridge?" For Natural Sciences, a subject-focused interview is much more useful as this is exactly what your interview will be like. I had a "general" mock interview where I was asked to "tell [them] about a banana" which was just a waste of everyone's time! Online mock interview videos, particularly the one by Churchill College, are reassuring to see what a real interview is like. 

The NSAA is all about speed - quickly spotting the key to the problem and spotting an easy method to work it out not requiring time-consuming calculations; other applicants I knew didn't appreciate this and actually weren't offered interviews despite having great potential! You certainly have to be very strict with yourself over how long you spend on each question and which ones are worth skipping as they'll take too long! As such I'd recommend doing all NSAA past papers under timed conditions as this is the real challenge (afterwards going back over to make sure you can understand all the questions). Since there aren't too many NSAA past papers, I'd recommend the ENGAA which has a similar format, and the PAT from Oxford.

In the weeks leading up to the assessment I also tried to do most calculations by hand in A-level classes, which was great preparation and much more fun than you might think!

The earlier you start preparing the better, especially with problem-solving - the skills you need to succeed build up slowly over time!

It's crucial you enjoy the subject you're applying for, and that you know you enjoy it. Hence starting early means you have time to discover if this really is a subject that you want to study, and also time to discover other subjects if you think this one isn't for you!

The final thing is to try to enjoy the process! There are a lot of hurdles to overcome, but regardless of whether or not you get an offer you will grow so much as a person and see vast benefits on your A-level studies, so just keep this in mind if the process seems daunting! Just give it your best shot and be confident in the fact that you'll come out the other side much stronger!