Hi, it can seem fairly scary but actually it was not as bad as I thought it was going to be. you are briefed before going in. you will be put into little sections with wall dividers and you will complete the task in each area in a small amount of time, you then move on.
Do not look around the room when you are done as a few people got told off for this. Also if you can hear other people, do not let their answers change your mind as they may have it wrong.
Good luck