Dissertation committee and the role they play in coaching the learner to complete the dissertation.?

Who are the three members of a dissertation committee and the role they play in coaching the learner to complete the dissertation.?

Committee members are responsible for reviewing thesis and dissertation drafts, and providing feedback in a timely manner.
Depending on circumstances, there should be no more than a four- week turnaround review time for each of the committee members to review the manuscript for a thesis or dissertation.