Stage 2 is a
structured interveiw, so is probably unlike any interview you have had before. It consists of a series of questions (around 50 if I remeber correctly) of which the interviewer is looking for a particular answer. Sometimes this could simply be a yes/no answer, such as "Are you a determined person?" Then you may get asked why, where you can start to elaborate, but generally the interviewer will stop you when they have the answer they require.
Stage 3 is when you get the chance to really show who you and elaborate to your hearts content!
