I'm currently developing my dissertation proposal, and am in the process of choosing my committee members. I have heard that one should carefully choose their committee members, since they ultimately judge if and when your PhD work is done. As far as I can tell, a committee member should at least have some expertise in my research topic. I'm sure there's more to it than that, but I want to know what other qualities should I look out for? What qualities in a committee member should I avoid? I imagine these other qualities are subtle and difficult to judge at first. Nonetheless, how do I know if they are a good fit for the success of my PhD?