Natural Sciences Admissions Assessment; 2x interviews.
Interview 1: discussion on preferred course modules, subject-related problems; Interview 2: single extended problem.
Mock interviews, recapping personal statement and A Level content.
Be honest about what you don't know; don't be afraid to pause for a while before answering.
Remember this advice isn't official. There is no guarantee it will reflect your experience because university applications can change between years. Check the official Cambridge and Oxford websites for more accurate information on this year's application format and the required tests.
Also, someone else's experience may not reflect your own. Most interviews are more like conversations than tests and like, any conversation, they are quite interactive.
Test taken:
Number of interviews: 2
Time between interviews: 20 minutes
Length of interviews: 30 minutes
Online interview: No
My first interview started with a discussion on which modules I thought I would be likely to take (this put me on edge a bit, because I couldn't remember the course structure exactly). We then went through two or three problems, with me being prompted to the next stage of each.
My second interview worked through a single extended problem, considering it in different situations and considering different parts of it. Again, although I had to provide the thinking, I was guided into each part of the problem, and each bit was quite small.
Before my first interview a random professor showed me his office, and explained a bit about what his work focused on. Pretty random, but a nice way to settle the nerves.
I had two
I did two sets of practice papers, available from the uni website. These really helped me work out which sections I was most likely to do, although I found the actual test quite a bit harder than the practices (although everyone else said that as well)
I got a bit flustered about trying to prove myself. In the first interview, I should probably just have said that I couldn't remember exactly what parts of the course there were. I think I would have enjoyed it a bit more if I went in completely honest from the start.
Prepare yourself to sit in silence if you need to think for a moment before you explain what you are thinking: it feels really awkward but if that's the way you need to think then you might as well (also, one second will feel like ten but it's really not that long).