During the assessment centre there are two group exercises and one individual interview.
I personally found the first group exercise not really good and not stimulating.
The one-to-one interview was also not a very positive experience. The only question that the interviewer asked about my application form (full of achievements and professional information) was a personal very generic question. This left me quite disappointed as I thought an IBM interviewer would be more interested in investigating and learning more about my past experiences rather than JUST ask me where I was from. The rest of questions were just standard competency and commercial questions. It was mainly a question-answer type of interview, without a real discussion.
The HR staff and the recent graduates were however really nice and welcoming.