Anyways I'm going to give a detailed overview here, since I am lazy and when everyone asks I can just give them a link instead of having to explain the process over and over again. This is actually not as short as you might initially expect, so bear with me.
A Ph.D. is a "Doctorate of Philosophy" degree, and is often the highest degree you can achieve in a field. As above, I'll be using the terms Ph.D. and doctorate interchangeably, though there's technically a slight difference that nobody cares about (if you're a trivia buff, Wikipedia has all the answers). The term "philosophy" in the Ph.D. does not refer to the actual field of philosophy but in the broader sense according the Greek meaning, "love of wisdom". Once obtained, you are awarded the title of doctor, which means you get to put "Dr." instead of "Mr." or "Mrs.", etc. on all those government forms you fill out. Yes, that means people should address you as doctor, though colloquially in English (at least the America's as far as I know) doctor usually means a medical doctor.
If you want to apply to a Ph.D. program at a university, you must go through the same awful application process you did when applying for a bachelor's or master's degree. You'll have to fill out an online application that is much longer than it needs to be, write a couple of useless essays, take some painful standardized tests, and write a personal statement (probably the only part that should matter). For the standardized tests, this means the GRE in the United States (very similar to the SAT) though different fields have their own requirements (e.g. LSAT for law school, MCAT for medical school).
Once you're in, obtaining that shiny piece of paper that says you're a doctor generally requires taking three exams. It's important to note that different schools and different fields will have slightly different requirements. This makes some sense since measuring knowledge varies across fields (e.g. explaining the significance of Elizabethan poetry and proving some mathematical theorem). The three exams are:
- Qualifying Exam
- General Exam
- Final Exam (commonly called a "defense")
And yes, they are called "exams" because they are in every sense of the word (you're basically graded on your performance), which means you can fail them (usually that doesn't happen, though again it varies by where in the world you are and by school and by department).
Let's go through each of these in order.
1. The Qualifying Exam
The qualifying exam is a test given by your department containing questions from graduate level coursework. Usually you take this test the second (school) year into your Ph.D. program. In the first year of school you are usually just taking classes, similar to undergrad, though grades don't really matter and the classes are more intensive. As with any degree (including high school), there are required classes you must take, and some total amount of coursework credits you must reach before you graduate.
The questions on the exam are written by the professors in your department and are supposed to be hard (not simply stuff you did as homework in their classes). The test is take-home, you'll have about a week to do it and can use any resource you want, though google probably won't be as much help as you would like.
There's a lot of variation to the test across departments, but from what I've seen there's usually a bundle of questions (8-12) and you must choose 3-4 to answer. As you'd expect, you'll answer the questions that correspond to the coursework you have taken and enjoy. Some departments might force you to answer certain questions, corresponding to coursework that is required for all students. As an example, in my qualifying exam I had to write a couple of math proofs, do some statistic analysis (anova related, though much harder) and write a 20 page paper on some inefficiencies in the US health care system (quite easy given how many there are!)
After you submit your answers, you'll present what you did orally to a committee of department professors (usually the ones who wrote the questions you answered, plus an extra one or two to make sure nobody is delusional). This is to make sure you actually understand all the material, then they will grade your performance (pass or fail). If you fail, it's not the end of the world as you can usually retake it, provided you are committed enough. Some departments will make you do corrections if you did something wrong.
Once you're done with that it's on to the general exam.
2. The General Exam
In short, the general exam is submitting a proposal for your dissertation (also called a thesis). A dissertation is a collection of your original research and findings (though most people know it as that thing all the grad students are complaining about!) You need to get a group of professors (called your "committee") to evaluate the worthiness of your thesis. They will decide if you pass or fail your general exam (as well as your final exam).
When you start your Ph.D. program, you usually have some idea of what you want to do research in though it's okay if you don't. Keep in mind that fields are very broad and are made up of a bunch of specific topics (for example, math is made up of algebra, geometry, set theory, etc.) During your first year, you will meet with professors and learn about their research topics until you find something that interests you. When you agree to work under a professor, that professor becomes your "advisor". Some schools will require you to submit this information (what you want to research in and who you want your advisor to be) when you apply.
Once all your coursework is completed (1-1.5 years) you'll just be doing research. That means that a majority of a Ph.D.'s schooling is not taking classes (so if you know one, you don't need to ask if he's taking classes because he probably isn't!) How much research you need to do before taking your general exam varies by school and department.
Your general exam will be a long document (probably 40-60 pages, definitely way more for some fields) which will contain what you've done so far, what you plan to do, and why it is relevant. Then you get a committee to evaluate it. Your committee will consist of either 3 or 4 members (you guess it! It varies by school and department):
- Your advisor.
- Another professor in your department (or your co-advisor if you have one).
- A professor in a department that's NOT yours.
- Anyone (who knows what you're talking about).
The reason the third member must be a professor outside your department is to be an unbiased tiebreaker between the first two. This rarely happens now, but in the olden days it was quite frequently the case that you didn't really have a choice in your committee because there were so few professors (and even fewer who knew what you were talking about it). If the two professors in your department happened to hate each other, it was possible that one would fail you out of spite to your advisor. The professor outside your department would be able to settle the dispute.
Did this situation actually happen often? Probably, given how few professors there used to be. Furthermore, since professors essentially have an objective measurement that proves they are the smartest people in the world, they are bound to disagree with each other and be egotistical about it. Nowadays there's plenty of professors and universities to go around (and plenty who probably know what you're talking about) so if you know that two professors do happen to hate each other you can easily find a substitute.
Note that your committee needs to be approved by your department and/or the graduate school. Unfortunately that fourth person on your committee can't be your roommate, your mom, that cute barista at starbucks, or that homeless guy sitting next to you on the bus.
You'll set a date with your department to take your general exam, and you'll give a copy of your proposal to each member on your committee a few weeks beforehand so they can read it. On exam day you'll give an oral presentation about what you did and your committee will hopefully grill you about it. Afterwards they'll discuss whether you pass or not.
Think of the general exam as a contract. You say, "here's the research I've done so far. Here's the research I'm going to do. Here's why it is relevant. If I do this then I get a Ph.D." Then your committee either says "yes" (pass) or "no" (fail).
Colloquially, someone who is getting a Ph.D. and hasn't passed their general exam is a "Ph.D. student" and someone who has already passed their general exam is a "Ph.D. candidate". If you've ever heard students talk about candidacy this is what they're referring to.
3. The Final Exam
Once you've completed all the research you said you were going to do in your proposal, you collect your findings into your dissertation and take your final exam. On this day you'll get your committee into the same room together (a very hard thing to do) and you'll give another oral presentation on your findings. As before, you'll give a copy of your dissertation to each member on your committee a few weeks before the exam date so they can read it. Then your committee evaluates and decides whether you are Ph.D. worthy or not.
Your dissertation will probably be anywhere from 60 to 400 pages (smaller for physical sciences, larger for social sciences like history and literature). Your advisor usually won't let you take your final exam unless they know you're ready. It's commonly called a defense because you are defending the stance that the research you have performed is worthy of getting a Ph.D. If your committee has deemed you worthy, you are now officially a doctor!
It's important to note that general exam's and final exam's are open to the general public. The reason for this is that the public should not be kept in the dark about the research that goes on in academia. Thus you can walk into your local university, go to a department that interests you and ask the staff if there's anyone taking their general or final exam. If there is you'll get a time and place where you can listen to the presentation (you'll have to leave when the committee debates their decision though). Of course, good luck understanding anything if you do attend (people aren't getting Ph.D.'s because of their public speaking ability).
I didn't cover any of the finances with regarding to getting a Ph.D. as that would be equally as long and frustrating. Best left for another time.
Why haven't I graduated yet? The hour I could have spent today working on it was instead used to write this. Hope you learned a few things! I can answer any questions if there are any.