PinkPig said:I think you'll find that, with a few exceptions (medicine and vet courses, other very popular courses here and there), Oxford and Cambridge interviews are rather different to any other university interview you're likely to have.
That's what I thought, especially after 2 "interviews" at Birmingham and Bristol turned out to be little more than recruitment drives on their part. So I walked into UCL expecting the same and got a complete grilling that completely threw me (and which contrary to other posters thoughts did include questions from my Maths and Further Maths A-level syllabus, a couple of which I got wrong!) and thought I had blown my chances entirely. Just goes to show how little you can tell about your performance in these things as I got my offer through the post a couple of days ago. So as for advice, especially regarding the UCL interview, I recommend you walk in with a good recall of pretty much everything you've done so far in the syllabus (which I expect you already have if you're being interviewed by UCL), but also be honest about what you do and don't know. What I found was most important however was to try and get the interviewer to like me, once I felt I had him on my side even when I found myself floundering I managed to get the odd laugh out of him and I feel that had something to do with getting my offer.
Most of all though, relax, don't worry about it and I'm sure you'll do fine. Good luck!