answer:Generally, there are three years of classes. I think that’s around 3 classes per semester. During that time you take methods courses and probably have developed a research proposal for your dissertation. After that, the fastest people take a year to gather data, analyze it and write the dissertation. Usually people take two years to do that, and it is far from uncommon for people to take 3, 4, 5, even as much as 9 more years to finish their dissertation. How much time it takes depends on how much time you have and how motivated you are and how much time your department allows. Most graduate students have to work and many have families and all those things take time away from research. That’s why things can drag out. Sometimes the people who let it drag out are disorganized or not well motivated. Sometimes it’s just life. In either case, the department generally won’t let this drag out forever. Then you finish in the time allotted, or move on somewhere else.