2x20 min interviews in 1 day
Combination of connected and unrelated questions
Practice answering questions with other people or yourself
Say everything you're thinking that's relevant to the question
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: None
Number of interviews: 2
Time between interviews: 1 day
Length of interviews: 20 min
Online interview: No
At first, I was asked for something simple in my personal statement (likely just to check that I knew what I had written about in it). I was also asked "what did you learn about in this online course" (which I had written about in my personal statement). Then I had the questions. These were all biochemistry related questions (from biology and from chemistry at school). In one interview, I had a question which they then continued asking deeper questions on this topic (I found this very interesting!) It started off with simple high school knowledge, and then used that knowledge to understand more (but again, I was just using logic to go through it). In my 2nd interview, these questions were shorter and unrelated to each other, and we basically went through these set of questions one after the other. As I had been practising questions in my head before, the transition into the real interview was smoother, and I felt more comfortable. Secondly, you should actively believe that the things you are talking about or discussing with them are interesting! When you are very interested, it shows, and you are also more confident and also are curious to learn more! Otherwise, (for me), I found it more relaxing to smile (at okay moments of course), and I even laughed at one point because I said something completely stupid (something along the lines of "when you add oil to water, the water becomes ice"). You shouldn't make a mistake on purpose, but laughing for a second with the tutors did relax me. If you do make a mistake and you realise, I would say take it lightly - and definitely don't stress because this will affect the rest of your interview. The rooms are quite cozy. I had 2 interviewers for both interviews, and one was generally more silent and taking notes, and the other was asking the questions.
I asked someone who does biochem at Oxford to do a practice interview with me, as well as asking my chem teacher for one too. Maybe chem teachers might not know the system well, but you can definitely find oxford students through OxBuddy and other free tutoring systems. I, of course, revised the topics (bio AND chem) (I actually had exams at school around the same time so 2 birds with the same stone!), and looked again at the things I wrote in my personal statement (to check I can answer questions on it). I looked at several New Scientist articles (or other science magazines - it doesn't have to be Nature or Science, just something to get you to know some topics of what's going on) - although in the end I personally didn't get asked on this in my interview. I watched the youtube videos there are on "Oxbridge interviews" and "biochem interview questions" to understand how it will be. It might be weird to be talking to yourself, but really this is I think what helped me the most. I had a whiteboard in my room during interviews so I practised for example by looking up questions (there are a lot of them on google if you search, e.g. https://sites.google.com/site/oxbridgeinterviewquestions/biochemistry), but also you can make up your own questions (e.g. "What happens in my body when I eat salt? What about sugar?" "How could I test for whether there is horse meat in my meat" or other random questions - you can even have questions which don't have an answer, or are really stupid! As long as you can try to use logic on them (ideally biochem-related so you can use biochem logic)). I was doing this (in my head) until when the interviewers opened the door to greet me. I was just going through questions and answering them alone. This was very helpful because when I actually got into the interview, it just felt like I was continuing on smoothly from my own questions, and I was confident my brain was up to speed. I was also confident that even though I might not know some of the answers to questions, I would be able to logically go through them and think about it (and I know I can do this because I had been answering stupid questions with no answers beforehand by myself!) Also, doing questions in your head takes your mind off the stress so it kept (at least me) calmer.
When you get asked a question, it's a good idea to say everything that you are thinking so that they understand your logic (e.g. once you get the question, start by saying "Well I know that [this] and [that], so I would think that [this happens], which maybe leads to [this].") And if you learned about "this" or "that" in some interesting book or online course or something, then you should mention "which I read/learned [here]"! Your answers don't have to be true or correct! And you can even say "I'll *assume* that (e.g.) the volume of water in this cup is 50ml" (or whatever else you want to assume!) They want more of how you think and how your logic is, than what you get as the final answer. If you don't know something, you should try logically saying e.g. "I'm not sure what this molecule is, but I remember this group looks like an amino group, and that has some specific properties so... [blahblah]" The interviewer will tell you if they notice you really need this information. Make up questions and answer them in your head until just before the interview, so that your transition into the interview is smooth. Have fun and take this as an opportunity to learn from the tutors! This may be your first time talking to world experts on your subject! Take it as an experience and an opportunity. You should have learned something during the interview! And this is also how tutorials will be (except for the fact that you already know the topic beforehand, you would have prepared on it too, it doesn't feel like your life depends on it (which interviews don't actually! so it's ok!), and you know your tutor, so definitely a lot less stress), so it's nice to have a little taster. Have fun in general if you go to Oxford for interviews! Meet new people (please don't be meeting them to judge "how good you are compared to them" and also be friendly and come out of your room).