There were about 12 people in my assessment centre group, each of them had a Master's degree (except from me) and I found this quite strange! Anyways, for me this was the 1st assessment centre and I found it quite stressful in the beginning! There were about 6 people watching you and they take notes of every single word you say during the group excercises! Quite daunting! They watch very closely your BODY LANGUAGE so try and be positive and smile at everyone at any time! Try to aknowledge the contribution of each member of your group ! You have to show leadership behaviour but at the same time you should not seem like imposing yourself on the others... The exercises would almost always require knowledge of a multiple of business functions i.e. marketing, finance etc. Try and take part in ALL discussions even if you don't feel as an expert in Finance (let's say) compared to someone in your group who has a MSc Finance degree! You have to appear confident and competent in EVERY ASPECT of the task never mind the division of tasks within the team! Otherwise they would grade you down! They will ask for a lot of written feedback after each of the exercises so think about how you could show some self analysis! They will be judging your analysis skills, presentation skills... everything! BUT always from the perspective of their VALUES! So try and always focus on showing how you are customer obsessed and incorporate all the things they stand for! Because in the end, the feedback will be structured around those values!