The PhD (also abbreviated Ph.D.) degree is considered by many to be the ultimate academic degree that one can obtain. Ph.D. actually stands for Doctor of Philosophy but it can be obtained in many different areas of specialization. This article addresses primarily the Ph.D. as it exists in the United States. Other countries also have the Ph.D. degree, but may have different requirements and characteristics.
Even within the United States, different institutions that offer the Ph.D. have different requirements and procedures, but in general most have the components (whether they used the exact same terminology as this article or not) described here.
Choosing a Ph.D. Program
Different institutions offer different specialties and programs. They also have different entrance requirements, and have different degrees of credibility. An important consideration to take right up front is that ALL Ph.D. programs represent a significant investment of time and resources. Therefore, it is important to choose a program that really meets your needs. If you are going to go to all the effort of getting a degree, you want to make sure that it is aligned with your interests and needs, and is highly respected in your field. It is no shortcut to take an "easy" program if the result is not widely respected.
In general, a Ph.D. represents a specialization. So, one of your first considerations is to find what schools even offer degrees in your interest area. Keep in mind that different programs may have different names for very similar things. So, just because you don't see a certain term in a catalog or on a website doesn't mean they don't offer something of interest to you. In many ways, the Ph.D. program is carried out in a similar manner as an apprenticeship program where you are an apprentice for your research advisor. As such, many students choose their program in order to work with a specific professor at a specific institution. Others may choose a university based on the strength of the faculty in their interest area. Those are the most compelling reasons to choose a program, but sometimes more mundane, logistical concerns can play an important part. For example, for students who don't have the option of relocating, location can be an overriding factor. Sometimes, a student can arrange with their local university to also participate in another program either via distance learning technology, or by spending some amount of time at the other location. Some programs support a completely online Ph.D. Of course, not all universities have the same entrance requirements and some are more selective than others. Thus, it may not be possible to attend your first choice if you are not accepted into their program.
Almost all Ph.D. programs require you to already possess a bachelor's degree. Many also require a master's degree, but not all of them do. Some programs require that your undergraduate degree was in a specific field, or that you have taken certain courses prior to beginning your program. If you are currently in school, it is very prudent to investigate the entrance requirements to any program you might be interested in so you can take required courses while you are still in school.
All programs require you to apply for admission. Typically that application will ask for basic demographic information, scores from tests like the GRE (Graduate Record Examination), your academic and work history, grades, course listings, an essay of why you are applying, a statement of your research interests, and, of course, an application fee. It is worth it to take the application seriously and to present yourself in the best possible light.
After being accepted into the program, the student and faculty form a team of advisors who will serve as the student's "committee". The makeup of the committee can change throughout the student's tenure, but will ultimately become the student's dissertation committee when the student enters the research phase of their program.
Most Ph.D. programs have two basic components, each of which have several sub-components. In general, when someone graduates with a Ph.D., they are expected to exhibit mastery of their subject area, as well as a demonstration that they have the ability of conceive and carry out original research that contributes new knowledge. Subject mastery is achieved through a combination of coursework, testing, and self-study. There is generally a set of core courses that Ph.D. students are required to pass. Additionally, a Ph.D. student will be required to take a test near the end of their coursework that tests them on their breadth of knowledge. That exam might be called a core exam, a qualifying exam, or something similar.
When the student passes the coursework stage of their program, they enter the research phase. One of the first primary components that they must do is to determine what their original research will be. Of course, the student is working with faculty in the department to determine a suitable topic for their research. The student creates a formal research proposal that details the work they plan to do, demonstrates that they have done a thorough search of research literature so that they are aware of where their research fits into the larger picture and to ensure they don't duplicate work that others have done.
After the student has completed their dissertation proposal, they schedule an exam with their faculty advisors to have an oral exam where they "defend" the proposal. This is sometimes called the preliminary examination, or "prelim". There are other terms that might be used for this, but most programs have a similar exam regardless of what it is called. The outcome of this exam is that the student "passes" which means that they can begin their research work. Another outcome is that the student must change some things in their proposal, or, they can fail. Assuming they pass, the dissertation proposal becomes a blueprint for their research, and in many ways it becomes a "contract" between the student and the committee.
As the student begins their independent research they also attend seminars, they may take more coursework, or other activities that are agreed on between the student and the committee. As the student is doing their research, they begin writing their dissertation. The dissertation is a rigorous, academic document in which the student reports on the results of their research, their research methodology, and other important aspects of their research. The dissertation can only be completed after the research is done, but there is much that can be done along the way.
When the research is done, and the dissertation is completed, the student and committee decide a date for the final exam. The final exam is typically an oral exam in which the student defends their dissertation. This exam is often open to the public. The outcome of the final exam, or "defense" can be pass, some changes need to be made, or fail. Once the student passes the exam, the student deposits their dissertation and completes any formalities that are required by their department and committee. Ultimately, the student graduates with a diploma for their Ph.D.
In addition to the components listed above, some programs require other elements. For example, some programs require that students teach, or perform an internship. Some programs have a separate research methodologies component that a student must complete. There are many differences between programs of what all elements are required of the student.
In summary, getting a Ph.D. is a challenging, but highly rewarding experience. It can open new avenues for employment, and can enrich your life in many ways. Don't forget that it is a big commitment of time and resources, so you want to choose your program and research area carefully.