The Viva Experience

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.




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10 Responses to The Viva Experience

  1. @davidmpyle says:

    All sound advice!

    From my own experiences of examining, I’d just re-iterate one main point: examiners are not there to trip the candidates up, but they do want to have a conversation that starts by allowing the candidate to place their own work in the wider context of the field. So the beginnings – of the viva, and of the thesis – are both important for the same reason. Do expect the examiners to start off by asking for a short, ‘big picture’ explanation of what you have done, why, and what you have found out. And you should expect them to pick up on your introductory paragraphs and delve a little deeper.

    One example sticks in my mind. I was external examiner, and it was a hot mid-summer day. Being Oxford, both the candidate and internal examiner were in full formal dress (yes, sub fusc is still required), and already starting to feel warm. As we were about to start, the internal asked, glint in his eye, whether he might ask the first question. Feigning innocence, he began ‘so of course, you start off by telling us how X published the definitive work on this problem a hundred years ago. Now that some time has passed, can you tell us a little about what X wrote, and what we have learnt since then?’. This was, of course, the first reference in the first paragraph of the whole thesis – and the candidate had clearly never even seen the reference: in this case, a stunning book that would have been completely memorable, had the candidate ever ventured into the library stacks to find it, just a short walk away. Of course, we didn’t let the candidate squirm for long, and the rest of the viva passed off without any problems.

    I have just one other point to add. At the end of the viva, the examiners usually have to sign a form that says something like ‘we deem the candidate to have produced work of sufficient quality to merit the award of PhD’. There are usually fairly clear guidelines about what might constitute ‘sufficient quality’ in abstract terms, but the most concrete evidence for what ‘sufficient quality’ looks like are the runs of previous, successful PhD theses that line the library walls. It is for this reason that examiners pay close attention to detail when it comes to corrections, asking themselves the question of whether they would be happy for this thesis to become the benchmark for the next generation of students. In science, a meritorious thesis might well be little more than 3 or 4 published papers that are bound together – but that little bit (the beginning, and the end) is still important. This is where you tell the story (usually after the event), set the scene, and show that you can see how and where your new work fits in.

  2. Good piece, Athene, I think it sums up the process very well. There was a Times Higher article recently asking if the Viva was still fit for purpose, but I thought it was a weak piece that based its argument on the anguish of a few PhD students who’d had disastrous (in their opinion) Vivas. This is a good riposte to it, although I’m not sure you intended it to be?

    About the anticlimax argument, I can relate to that. One of my friends felt his Viva was a bit of a disappointment as he wasn’t grilled to the extent he expected to be about his work and the theories he developed. Instead the examination was more of a discussion of the field and he’d pre-warned me that I might not get what I expected in the exam. Indeed, I walked in and my examiner re-assured me that there was nothing to worry about, this would be a formality and then regaled me with a story about the morning after his own PhD Viva! Of course, I understand he was trying to calm me before starting, which I appreciated at the time, but I think afterwards I’d like to have been able to guess about the outcome for a little bit longer.* Otherwise, my Viva was perfectly fine, in fact he was so interested in some of my results that we published a joint paper on the work later on! Not sure if that is common?

    *Whenever I tell this to current students, they don’t understand why I think this, they’d all quite happily take that as the start of the exam.

    • I had seen the Times Higher Education piece but it wasn’t what prompted my post. I agree, it dealt more with anguish than facts. I often wonder if the science experience is different from humanities, where it is harder to ‘prove’ facts and so there is more scope for disagreement about arguments proposed. To add to your anecdote about what happened at the start of your exam, I once told a very nervous student (in this case a Master’s rather than a PhD) whom I bumped into on the morning of her viva, that she should go down to the pub and relax over lunch rather than fret. Apparently she translated this as ‘you had better go and drown your sorrows’ rather than that she had nothing to worry about! So that backfired somewhat….

  3. Dave Fernig says:

    Great post, will be adding a link to it from my “Rough guide to a PhD”, which doesn’t get to the viva. Most rewarding is when students come out of the viva, exhausted, but clearly having enjoyed themselves.

  4. Bob O'H says:

    Thanks for this. I’ll be doing my first viva soon, so this (& Simon’s) post are good preparation.

    The viva will be in Oxford, do I guess I need to check up on sub fusc. It sounds painful.

  5. cromercrox says:

    I shall tell all – I failed my viva at Cambridge. Moreover, I don’t remember what I was wearing. What had happened was that I had done a lot of preliminary work, missed a few months due to illness, and had come back again and started over, having assimilated all the earlier work. What nobody had told me was that you get so absorbed by the work that you imagine your preliminary work is generally known. Harsh words were said about my advisor, who was, looking at the matter from all angles and taking all factors into consideration, total crap, and hadn’t actually done a moment’s supervision. I went away, incorporated the missing work, re-wrote the whole thing, submitted it – and passed.

  6. Ginni Davidson says:

    Your piece is so at odds with my experience at my viva experience at Cambridge. I spent almost four hours desperately arguing for my ideas, my approach and my conclusions – I really had to defend everything. I’m still not quite sure if the work was passed, as I was given several pages of changes to make, without which the thesis would not be accepted; but the changes were so all-encompassing that they would require several months of primary research, a substantial change in the theoretical approach I took to the problem, and consequently the thesis to be entirely re-written. They insisted that I must use a particular source of data about the question, which has its own time-consuming analytical method, despite the fact that I had spent half a chapter carefully explaining why I had chosen not to use that source of data. In the viva I argued for this decision very well, and they seemed to agree with me, but I think the list of changes had been written before the viva, so that the fact that I’d won this point was disregarded.

    My supervisor (I had three supervisors in four years) was not familiar with my field, so his belief that it was ‘likely to be acceptable’ was perhaps incorrect. And I don’t think the right examiners were appointed; they should have looked for people more amenable to my approach, but again the supervisor was not aware of the background and prejudices of the people working in my field.

    In the end, of course, the list of changes was impossible. They wanted me to do another, different PhD. I never re-submitted, so have no degree of any kind, after (as an overseas student) an investment of something like £50,000. I wish I’d protested against what happened; but at the time, I was so crushed, confused and depressed I just ran away as fast as I could.

    My experience is not all that unique. Another overseas student at my college had much the same experience at his viva, and he didn’t re-submit either.

    • Ginni, I am so sorry to hear of your bad experience. You don’t indicate your discipline so I’m wondering if it was STEM or non-STEM. I have heard much worse stories about vivas in non-STEM disciplines than the benign (and typical) description I give above. However, I also wonder if the issues you had with your succession of supervisors were the root cause of your bad experience. A supervisor who IS close to the topic, does know appropriate examiners to call upon and who also will know if you are leaving yourself open to attack in what you write, should be available to every student. If a supervisor moves on to another institution that isn’t always possible, but to have 3 supervisors – who no doubt each had their own pet views about your work, with greater or lesser knowledge on which to base it – seems particularly unfortunate/unusual. Did your colleague likewise have a series of supervisors? It isn’t clear to me that being an overseas student should have been the least bit relevant (except that the expense would have been worse!)

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