Do they?

oh gosh, what a hideous thought. I have never heard of / known any one to.
But I wonder what happens if it all goes horribley wrong or you really disagree with the examiners?

While I am not currently doing a PhD, I'd have thought that any supervisor worth his/her salt would intervene and prevent the viva going ahead if you were going to fail. After all, it's not going to be something that is failed on the basis of one silly mistake. Having said that, if there's a fail option, someone must have taken it...

I asked my supervisor this too! I was told not, although obviously a major rewrite would not be good.

If you have a good supervisor you should be ok (that's what people keep telling me anyway).

I've heard of one fail, but apparently the girl had been told to get her act together many times so she had sufficient warning. Don't know the girl personally though.

I have never known anyone "fail" a viva, but I know people who got unexpected results (IE: referrals). Obviously I wasn't there but at least 2 of them were treated unfairly by their external, who thought that his/her way was the ONLY way of doing things.

The subjectivity of the UK examination process concerns me. I would prefer a public defence like those in place in Europe. I posted a thread yesterday about the possibility of recording my viva in case of a dispute - I don't think this is unreasonable. But everyone I speak to advises me against it. It seems ludicrous that something upon which so much depends cannot be recorded. I know there's an argument about it looking like you don't trust the examiner, but if you don't know them and what their examination reputation is like, why *should* you trust them?
Sorry about the soapbox, but I feel that there are just not enough procedures in place to safeguard students in this very one-sided system.

IMO, the argument that recording a viva belies a lack of trust in the examiner is like saying that keeping a receipt makes it seem like you think the shopkeeper is a fraudster. The examiner is (I presume) paid for the viva, and should have no complaints about it. Also, woulnd't it be nice to keep as a memento? I know I keep all my undergrad exam papers. Or perhaps that's because I'm sad...

Good friend of mine failed - not enough original material. This was an experienced supervisor too. And I know of others. I have heard that it is becoming more common, and suspect it is a particular problem for interdisciplinary PhDs. Although supervisors should be wised up enough to know what constitutes a PhD and to suggest appropriate examiners, i guess it doesnt always happen.

From what I understand, it is very rare to fail at the actual viva. Most supervisors would realise that their student isn't going to pass if they did get that far and probably stop them getting to that stage (or so you would hope).

I have heard of people getting through by the skin of their teeth but with major corrections.

I've heard of a couple of people who came out with an MPhil instead of a PhD cos the examiners didnt think it was worth the PhD

I don't think I could describe how gutted I'd be if I came out with an MPhil, which could have been done after a year, considering all the hard work I'd put in. WOuld be absolutely awful. Worse than failing in a way.

I've heard the only people who fail are the ones who submit against the advice of their supervisors for whatever reason. As getting to the viva stage looks bad for the supervisor too

That was my worst fear, coming out with an MPhil. Even though everyone said I wouldnt, there was still that fear in the back of my mind. I think I would have burst out crying in the viva if that happened

i guess it depends a lot on the country. in the UK i know people who got near-fails, ie. major rewrites without any beforehand warning. here in the netherlands where i do my phd, once you are given the green light for the viva you know that you cannot fail anymore. the viva itself is just a kind of weird historic play (with funny sayings like "Your honorable opponent, many thanks for your question").

In my country (Spain) I think it's extremely rare (not to say unheard of) failing the viva (which is more like a public defence) because if the examiners (which are 5 I think) think that the thesis is not good enough they would unofficially warn the student or his supervisor to have the thesis reviewed before a viva date is set.

The thing about the public defence is that (from the ones I've attended) it becomes rather a protocolary, bureaucratic act and the examiners would only say good things about the thesis and its author, hence losing an occassion of true academic discussion for the student.