I'm very surprised by many of the comments here implying that a PhD involves course work and exams. Is there a difference in PhDs between countries?
Here in Australia, the last degree involving exams and course work is the Masters. A PhD involves writing a thesis on new and original work under the supervision of your adviser. It usually takes 2 to 3 years. There are no exams.
I'd be interested to hear the perspective of those from the US and Europe.
US (and, I assume) Canadian schools typically have a PhD Candidacy exam. Until you pass the exam, you are not officially a PhD candidate. The format of mine was quite fair, I believe, and representative of whether or not one can do research. In December, we were told 15 papers that we needed to read. In January, we were given 6 questions based on those papers. The questions had parts, and they ranged in depth from, basically, "tell us what they did in this paper," to "poke holes in this work" and "compare/contrast the work in this paper with the work in this other paper." We were given two weeks. I wrote about 24 pages for that exam.
The candidacy exam is one of the exams the student got out of. There is, of course, then the proposal and the final defense.
In the UK, you don't take classes, because you don't take a Masters. You do three years in and out. Four if you struggle, but that's it.
What people are talking about here is usually the US system, where your PhD path includes Masters classes. You get a Masters along the way (I have mine in a drawer somewhere), but this is incidental along the path to the PhD. It takes 2-3 years to get those classes out the way, then you're all research. The system is the same as you are describing, except that Americans don't tend to split them up in their heads.
It must depend upon your subject and university in the UK. As a physicist, I have never known a student to obtain a PhD in less than 3 years. My students have taken 3.5 years minimum. There's one guy in our department who should get his PhD soon, after 8 years.
What you're describing is maybe how they are funded - but not the reality in my experience.
Please find anyone who has finished in 2 years in Australia. I know of exactly one person who finished in 3 years. 3.5-4 years is considered a "solid pace". A little less than half the students who started their PhDs at the same time as me (who didn't quit) are still working on theirs 8 years later (albeit part time).
I don't know anyone who's finished in 3, but you do occasionally hear about it. Never heard a reliable account of under that. Personally I think we don't tend to have course work in our PhD's because we don't have the student numbers to support it in most uni's and disciplines.
I was in a doctoral program (different faculty) at U of M. There was course work (basically 2 years at 80% of a full-time load), a teaching and a research apprenticeship and a candidacy exam before you were allowed to start work on your dissertation.
The absolute minimum time you could complete it was 3 years, but typically you were expected to take 5-7 years (though it was also expected that you'd be teaching at a university during the last couple of years).
Here in Australia, the last degree involving exams and course work is the Masters. A PhD involves writing a thesis on new and original work under the supervision of your adviser. It usually takes 2 to 3 years. There are no exams.
I'd be interested to hear the perspective of those from the US and Europe.