A graduate teaching assistant is an instructor who helps a professor conduct a college course. Sometimes graduate teaching assistants may preside over their own course, with simply some guidance from a professor. A graduate teaching assitantship is not a life-long career. It is simply a job that one is able to have while they are attending graduate school. After one is no longer in enrolled in graduate school, they must cease their position as a graduate teaching assistant. Most graduate teaching assistants have further career goals of becoming a college professor or university researcher.