I had my interview in Skipton. It probably took around 3/3.5 hours. I had to take 2 GMAT tests, have a face-to-face interview (lasted about 40 mins), and take the last 2 tests. The interview itself was pretty friendly, normal questions about your cv and your academic career and a few competency based questions (usual ones). The 4 GMAT tests were: - 2 quantitative - 1 deductive reasoning (quantitative) - 1 verbal reasoning You get 1 point for each correct answer and -0.25 for each wrong one. Each test has to be completed within 30mins. If you do some practice on GMAT tests, you'll find these pretty easy.

As others have said the interview is split into two parts; you take a series of GMAT style tests (3 quant and 1 verbal) and then have a fairly short and informal interview. The questions within the tests are of varying difficulty and there is negative marking. The interview is pretty easy, very general questions in regards to your past experiences. Whether or not you get selected appears to be entirely dependent on your test scores however, and so do not expect a good interview to make up for any shortcomings in the tests.