By The Princeton Review
Master's programs are designed to give you a solid education in a specialized field. Most master's candidates spend one to two years earning their degree before returning to the professional world. A handful continue on to earn a PhD.
PhD programs are designed to give you extensive expertise in a specialized field; they train you to pursue a life in academia as a professor or researcher (although many PhDs do not follow this path). Most candidates spend five to six years earning their degree.
PhD programs often offer full scholarships and a living stipend. Master's candidates receive less financial help; in many cases, they receive none at all.
Remember that within some programs, you can enroll for a master's degree and later choose to pursue a PhD if you are so inclined; conversely, you can enroll in a PhD program and leave after earning your master's if the academic lifestyle fails to entice you further.
The path to a master's degree
First year master's students take courses to fulfill degree requirements, just like in college. However, the workload is heavier, the course topics are more specific and much more is expected of you than in college. At the beginning of the master's program, you choose (or are assigned) a faculty member who will serve as your advisor. This person will help you develop an academic focus and potential topics for your thesis or final project.
As a second–year master's student, you decide on your research focus and—in one semester or two–complete your master's thesis or final project. If you show promise, you may be encouraged to continue toward a PhD.
The path to a PhD
In the first three years of a PhD program, you take courses to satisfy your degree requirements and gain a broad knowledge of the field. You choose an advisor and write a dissertation proposal, and you develop a working relationship with other professors in your department. Most doctoral students also work as teaching assistants for one or more undergraduate courses during this time, and some work as research assistants.
At the end of the second or third year, PhD students complete a thesis, take comprehensive exams or both. The thesis and/or exams demonstrate your qualification to continue with doctoral work.
In years four through six, you take fewer (or no) courses and focus on writing your dissertation, which is supposed to constitute a new and meaningful contribution to knowledge in your field. Needless to say, this is quite a bit of pressure, and most students spend much of these years in the library. You're not totally isolated, however–you work closely with your thesis advisor and others in your department to revise and refine your dissertation.
When you've finally finished, you are required to present and defend your work before a faculty committee. Rarely does anyone fail a dissertation defense. After all, you should know more about your subject than anyone else in the room. If a committee member does uncover a flaw in your argument, you can generally address it in your revised dissertation.