I’ve seen a few posts around recently from anxious PhD students approaching their vivas in fear and trepidation or discussing the experience in the immediate aftermath. For instance, here is @hapsci discussing things after the event in a state of post-exam exhaustion and fellow OT blogger Erika Cule sought advice from her OT colleagues over twitter and posted some of the responses here. So what’s it like from the other side of the desk? I thought I’d pass on some thoughts from the point of view of someone who has examined a good few theses in different universities, even in different countries, as well as across a range of disciplines.
Firstly it is worth pointing out the failure rate is tiny! The expectation on the part of the examiners (at least in science subjects; it is possible this isn’t true in arts and humanities) is that the thesis will have had a good going over by the supervisor and is likely to be acceptable. So, the primary point of the viva exam itself is to check that the student has done the work and understands the words they’ve put on the page, not just copied them from elsewhere. Those two statements are not trivial. I have participated in an exam where it was clear from the outset that the work was not all the candidate’s own. The internal examiner (not me) knew the background and so knew that a significant part of the work – some computer simulation – was based on a computer programme that the student had had no part in writing: they were merely using it. In itself that was no big deal. That the student took the best part of an hour to admit that they were using the work of others without attribution was the problem. Once they’d made that admission, and agreed to make this fact clear in the text, we could move on.
‘Understanding the words they’ve put on the page’ is even more frequently an issue. If your thesis is about X-ray scattering and you can’t explain the basic principles, you can expect a good going-over from the examiners. If your key experiments use NMR and your description about precession or relaxation processes is woeful, expect problems at the start of the viva. The candidate may believe the exam should be about the work they have done; many will be prepared to discuss the minutiae of their experiments until the cows come home. They should realise the examiner may not be an expert in some of the techniques described but be anxious that the student can place their work in context and explain it. In my experience, those of my students who have had a hard time at their viva have suffered at the start of the exam because they can’t do this clearly for the basic ideas or have never actually sat down and read the primary literature they quote so glibly. Be warned!
So, what’s the best preparation for the big day? Firstly, don’t worry about what you wear. The examiners don’t care as long as you turn up looking like you’re taking the exam seriously. I would not recommend a T-shirt and jeans, nor would I feel a 3 piece suit or a little black dress is a requirement (unless in Oxford sub-fusc is still required; I don’t know about that). Smart and comfortable are probably the watchwords. Secondly, undoubtedly read your thesis carefully. If there’s a gap between submission and the viva, which may often run to some months, you have probably forgotten details which you need to get stuffed back into your brain. Additionally, do think where the obvious ‘big’ questions are. I’d include in this category
- Why you did this work?
- What were the most important things you found out?
- What are the basic underlying principles?
- What would you have done differently if you were starting again?
- What do you think are the next experiments that need doing to follow up on your work?
These questions are all pretty obvious, but can still flummox people. By the ‘underlying principles’ I mean all those basic ideas about the techniques, as I mention above, but also how thermodynamics, genetics or whatever is relevant. In my field, if discussing polymer mixtures, for instance, you need to understand concepts such as entropy of mixing. Even if the phrase barely appears in the text, you should be able to go back to first principles. Often students can’t. They’ve taken the basics as read and can be made to feel very uncomfortable.
Examiners try to set candidates at their ease, but if the first questions asked – why did you do this piece of work and what are the key things you learned – cause the student to go red in the face and mutter ‘I don’t know’ the viva gets off to a very rocky start. But by and large examiners do not ask trick questions. I have never yet been paired with one who is simply out to trip the student up, look aggressive and display their own brilliance. On the other hand I have, not infrequently, been paired with one who talks a lot about their own work, thereby giving the candidate little opportunity to open their mouth. I find this sort of behaviour frustrating, but it may make the examinee’s life easier since if they don’t open their mouth they can’t put their foot in it.
I suspect the most common reaction to a viva is in fact a sense of anti-climax. Was that it? After all those months of slaving away, it’s all over in a couple of hours. (When I set out, PhD exams were customarily more like 4 hours and often more; the average time seems to have plummeted and the guidelines my own university offers examiners make this expectation clear.) Maybe you will come out of the viva feeling like Groucho Marx:
I don’t care to belong to any club that will have me as a member
Certainly I recall one student quoting that to me after his viva, but as he is now a highly successful professor I doubt he actually meant it. Some students feel cheated they weren’t given a harder time of it, I’ve heard that view expressed too, but then there are at least as many who come out sweating about the errors that were uncovered or the pressure they had felt under.
So what do I think the point of the process is? Definitely to establish that the work is the student’s own. If substantial plagiarism had occurred, I think it would readily become apparent and that has to be a crucial component during the examination. It is also important, I believe, to get an external objective view to help the student put their work in context. That is why, at least in general, the supervisor is not part of the examination process although in some universities they may be physically present in the room. It is useful to get an outside view as to whether some new hypothesis or interpretation looks convincing and to check there are no glaring errors or omissions (what, no error bars! That omission I’ve seen too often to count). It is unusual for there to be no corrections to be made, from basic typos, to missing citations, to something more fundamental. In general these tend to be easily fixed. You shouldn’t feel bad if you’re given pages of corrections to be made, that is pretty much the norm.
What if you yourself discover an error before the exam? Turning up with a list of the typos you’ve found is often to your advantage: it saves time and looks as if you’re taking things seriously. But if the mistake you’ve found is more fundamental – perhaps you’ve screwed up your statistics or misinterpreted a line in a spectrum – then being open about it, preferably in advance, is a good idea. Send the examiners a note of what the problem is, whether it makes any difference and a statement of how the problem can be sorted out (even a completely rewritten few pages you’d like to replace in the text) means that the difficulty can be faced head-on without embarrassment. These things can happen, but they shouldn’t be too serious – unless of course it undermines the whole thesis. I have never seen that happen.
Vivas in other countries can be very different from the UK. They are often done in public and are much more of a formality (in The Netherlands requiring full academic dress in my experience), less of a serious conversation about the science. I have found that quite frustrating myself, as it becomes a performance for all parties rather than an exam. In the UK I would say they should be regarded as an important staging post but not an anticipated nightmare that makes you sweat for weeks in advance. Probably few people (on either side) actually enjoy them, but they nevertheless can stimulate an interesting debate about your research of a kind you may never get again.
Between writing and posting this blog I came across a post entitled ‘Are PhD examiners really ogres?‘ from entomologist Simon Leather. Its angle about vivas is rather different from mine, in that it concentrates on how examiners behave rather than what they might expect, but it also covers some similar ground: your viva should not be something to fear.