How does one decide one's place in a group or community?

When one finds themselves in a large group situation such as a school, online community, church, social organization, etc… how does one determine their value in the group and their role in it? What sort of parameters or measuring stick (if any) can a person use?

I am going to withhold my personal opinion, because, I am not looking for affirmations or rejection of my perceptions as much as I want to hear what people think.