1x 30 min Skype interview
Economics: game theory; Philosophy: role of models in science and social science; Politics: revolutions
Past papers
Made use of freely available online resources, and read some books on philosophy.
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: 1
Skype interview: Yes
Length of interview: 30 minutes
I had 10 minutes with each
I used the official practice papers that Oxford provides.
I made use of online, freely available information. I read a few books for philosophy (basic 'intro to philosophy' books, like 'Think'), because I was nervous about it, not having done philosophy formally at the school level.