The end is nigh – you’ve finished and submitted your thesis. Now you’ve got to just get that doctorate…I must warn you all at this point. I’m aware that the assessment system for PhDs varies greatly between countries. Having only got one PhD, I can only relate my own experience (which of course are relevant for UK PhDs). For example, Australian PhDs have no oral defence (although the thesis is still assessed by two examiners), and other countries’ oral defenses are extended seminars given to a larger audience.
Here’s my second warning – I’m not going to tell you how to pass a viva. Honestly, I don’t really know how to pass your viva. I knew how to pass mine, and thankfully I did. It’s your subject, your field – you’ve written a massive document on the subject, and in the process of doing that (as well as the three or four years of prior research) you will know your stuff much better than you realise. My impression – based on the experiences of people I have known doing PhDs – is that anyone who can submit a thesis can pass a viva.
The trick is not to panic. As annoyingly trite as that sounds, it’s by far the most important thing. You will sit down with two academics (sometimes three depending on circumstances), and they will ask you questions that probe your knowledge to the limit. It’s well known (at least in the academic circles I walk in) that examiners will ask questions until you can no longer answer them. This means that at some point in the proceedings, you will get stumped by a question. Examiners typically do not consider their work to be done unless they can bring out that half-glazed/half-terrified look you get when the answer eludes you. There’s no point getting worried if this happens, because they’re not going to fail you on it.
Also, your examiners have been in your position before. They know the emotions you’re going through, and if they’re decent human beings they’ll be understanding. They might even indicate you have passed early on, and that the viva is merely to check that you did indeed write the thesis.
Take some water in with you (there might be some there anyway). Make sure you’ve had a reasonable meal before going in – there’s nothing worse than a growling stomach an hour in. Don’t do anything too silly – keep caffeine and alcohol intake to a minimum, and get a good night’s sleep beforehand. When you get into the room, as well as taking some water with you, take a little prepared speech. You will almost certainly be asked a question along the lines of “Can you summarise your thesis?” or “What is the most important result derived from your research?” It’s worthwhile to prepare a little speech to answer them. Getting going in these first few minutes with some well rehearsed patter is a great way to ease yourself into the viva.
The viva is an examination, but it is also a scientific discussion. My colleagues have all reported a sense of enjoyment at discussing their science in intimate detail. You’re probably never going to get an opportunity like this again to speak about your work, so make the most of it. As you get into it, you’ll find yourself relaxing, and the whole thing will move much more smoothly.
That’s about as much as I can advise you about the viva. Prepare as thoroughly as you can – read as much of the material you cited as possible; if your supervisor is willing, set up a mock viva to practise how to deal with difficult questions, and revise, revise, revise. Don’t forget to go in there well-fed, well-watered, and with a controlled amount of caffeine and alcohol. And relax – after this it’s all over!