Summarize:

. Being early will give you an advantage over some of the other interviewees, as it allows you extra time to meet the interviewers, take in the surroundings and settle yourself. Of course, others in the group may well do the same thing, so introduce yourself (see next). Be polite and exchange a brief chat to show that you're friendly and team-spirited.  Be aware that you will probably be wanting some space to compose yourself, and so will your fellow interviewees, so don't chew their ears off. If another interviewee is too talkative, invasive or even trying to psych you out, be firmly polite and explain that you need a few minutes to yourself before the interview starts and simply move to another part of the room. Usually group interviews are designed to see how you interact with other people so be courteous to your fellow interviewees. These interviews are interactive. Pay attention, as you will be expected to participate and any lack of participation or enthusiasm will be noted. . The interviewers will usually give an overview as well as detailed instructions. Some group interviews involve training and exercises involving several steps. For example, you may have to perform a mock sales pitch using the companies steps to a successful sale. Interviewers may be looking for leadership skills, but this does not mean talking over others or trying to be the loudest. Instead, act as a 'facilitator': say "Shall we take a vote?" and then count the votes. This shows that you are confident, but willing to listen to others. Again, if trying to show  leadership, delegate tasks to others. Don't try to do it all yourself: no good leader would do that, but if you can co-ordinate others, this works well.Take detailed notes if you are allowed to do so. Direct your pitch at everyone, and don't focus all your attention on one person. If someone hasn't said much, ask their opinion. This is great as it shows you are considerate and a real team player. (But don't defer to someone else when it's your chance to speak.) This is a good way to seem friendly and a little authoritative at the same time. Speak out, but don't cut other people off or go over your allotted time for the question or exercise. If you are broken up into small groups, realize that people will still come over from time to time to hear what you are saying. It might be nerve-wracking but if you appear morose you shan't fare well. Send a follow-up letter that thanks them for the opportunity and their time.
Arrive early Introduce yourself to the people from the company before the group interview begins. Stay polite towards your fellow interviewees throughout the interview. Be alert and ready for anything. Listen Be considerate. Give others a turn. Make eye contact with everyone at some point. Include quieter people. Praise others for their good ideas. Don't be shy. Smile. Be sure to say goodbye to the interviewers before you leave.