In most schools, the required time is five years. But in actual study, there are very few doctoral students who graduated in five years. Doctoral studies in the United States are very difficult and the future is uncertain. Therefore, the dropout rate of doctoral students is very high.
Studying for a doctorate is not like studying for a master's degree. Although the master's degree in the United States takes two years, twice as much as that in Britain and Australia, it is easy to read. However, the United States hardly regards master's degree as a serious degree, except MBA. For example, the master of our department does not need qualification examination, and the final graduation defense is not open to the public. A master's degree is generally regarded as a transitional degree.
Most domestic students apply to the United States for doctoral studies and two-year master's degrees. I have to pass the doctoral qualification examination in the middle. If they pass this qualification examination, they can enter doctoral studies. If they fail, they can only get a master's degree and finish their studies. Master's study is mainly based on professional study and research, laying the foundation for future doctoral study. In the doctoral qualification examination, students need to complete three papers on the specified topics within eight days. As long as one paper is judged unqualified by the tutor, students have to rewrite it. If there are more than two papers, students will completely lose the opportunity to study for a doctorate.