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.
Number of interviews: 1
Skype interview: No
Time between interviews: N/A
Length of the interview: 25 mins
I was asked multiple questions on two different topics. I had covered the first one at school, but the interviewer explained the topic thoroughly. I was then asked a few basic questions on the basic principles, and then a couple of more complex theoretical questions that didn't rely on my previous knowledge and instead required me to think about how it would work.
The next set of questions were on a logical puzzle (no computer science). Again, they started basic and got progressively harder. I got stuck on a question before the end of the interview. The interviewers gave me some prompts, but I didn't get unstuck before the end. I was not asked anything about my personal statement or why I was interested.
I never felt completely relaxed and I started getting a bit stressed when I was unable to answer the question. However, the room was quite cosy, and after the first minute I got quite relaxed (it helped that I found the first questions easy).
I had a couple of mock interviews. One with my computer science teacher, and one with someone I didn't know who came into school. Neither were particularly similar to the interview I received, however they were still good for getting into the mindset. I used the practice papers online to prepare for the CSAT.
I expected to be asked about the programming side of the course, rather than more theoretical and maths things. I also expected to be asked why I was interested, and spent a lot of time stressing over coming up with a good, non-generic answer. I wouldn't have bothered spending so long stressing over pre-done answers. Spending a little bit of time getting your thoughts together about such things would be good, but I'm sure the interviewers would've been able to tell and thus it's of no use to them. They're looking for people who are genuinely interested, and the best way to see that is to see them apply themselves rather than recite a canned answer.It'd be hard to find similar question styles of the correct level to practice for. However, it'd be worth spending a little bit of time trying to find some.Don't worry if you get stuck. If you get stuck then the