3x 30 min interviews (2 with 20 min prep time), over 2 days
Politics: newspaper article; Economics: newspaper article, problem, game theory question; Philosophy: personal statement, problems
Practice papers (timed and untimed); read the Economist and 'Think'
-
Explain your thought process.
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: 3
Skype interview: No
Interviews spread over two days (minimum 3 hour gap between interviews)
Length of interviews: 30 minutes each, with 20 minutes preparation time beforehand for politics and economics
Politics: I was given a newspaper article with questions. I had 20 minutes of preparation time, and was then asked to give a brief summary, answer some questions and comment on a graph. Broadly, it covered the topic of democracy.
Economics: I was given a newspaper article with questions. I had 20 minutes of preparation time, and then discussed the questions with some new input (involving a little bit of calculus). Then I was asked to brainstorm options and explain how to solve a specific problem related to game theory.
Philosophy: I had no preparation time. Firstly, I was asked a short question related to my personal statement. During the interview I was given a problem about necessary and sufficient conditions, and one related to the question of truth.
I did practice papers, with and without a time limit.
I also read the Economist and an introduction to philosophy ('Think'!). I would definitely recommend doing this because it made me feel more self-confident. But it was not really needed for the interviews.
Interviewers want you to explain your thought process step by step in order to understand your way of reasoning. There is not always one right answer, so make the best case for yours.