Tout ce que vous devez savoir pour vous préparer à votre viva – du moment pour commencer à ce qu'il faut faire le matin de l'examen.
I remember the weeks before my viva being a nervous wreck. I'd spent years workin up to this point, and suddenly I had to step back and defend the whole thing in a single conversation. To say it was a challenge is an understatement.
If that sounds familiar, good. It means you care. And the good news is that viva preparation isn't mysterious. It's a skill, and like any skill, you can get better at it with the right approach.
This guide covers everything: when to start, what to do, how to practise, and how to walk in on the day feeling like you belong in that room. Because you do.
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Many people start too late. They submit their thesis, take a well-earned break, and then panic three weeks before the viva when they realise they can't remember why they chose their methodology.
Start four to six weeks before your viva date. That's enough time to do thorough preparation without burning out. If you've got less than that, don't panic – you can compress the process. But if you have the luxury of time, use it.
The first week should be about re-reading. The middle weeks are for active preparation – answering [questions](/blog/50-common-viva-questions-and-how-to-answer-them), practising out loud, filling gaps. The final week is about consolidation and confidence-building, not cramming.
> If your viva is more than six weeks away, don't start formal preparation yet. Stay engaged with your field – read new papers, attend seminars – but save the intensive prep for closer to the date. You'll burn out if you start too early.
This sounds obvious, but most candidates don't do it well. You need to re-read your thesis as if you're seeing it for the first time – critically, with fresh eyes.
Read it in one or two sittings if you can. You need to experience the thesis as a whole, not as a collection of chapters you wrote at different times. This is how your examiners will have read it.
Annotate as you go. Use a printed copy or a tablet and mark up anything that catches your eye: arguments that feel underdeveloped, claims you'd now phrase differently, sections where the logic isn't as tight as you'd like. These are the places your examiners will probe.
Write a one-page summary from memory first. Before you re-read, write down your thesis argument, key findings, and contribution from memory. Then compare it to what's on the page. The gaps between what you remember and what you wrote are exactly where you need to focus.
Note your own weaknesses. Every thesis has them. If you know where they are before the examiners raise them, you can prepare thoughtful responses rather than scrambling in the moment.
Your examiners aren't a mystery. They're academics with published work, known positions, and intellectual interests. Use that.
Read their recent publications. Not everything they've ever written – focus on work from the last five years that intersects with your research area. This tells you what they care about, how they think, and where they're likely to push you.
Understand their methodological preferences. If your external examiner is known for quantitative work and your thesis is qualitative, expect questions about your methodological choices. If they're a theorist and you've done empirical work, anticipate questions about your theoretical framing.
Don't try to second-guess specific questions. Knowing their work helps you anticipate areas of interest, not exact questions. Use it to inform your preparation, not to script your answers.
> A word of caution: don't over-prepare for one examiner at the expense of general readiness. Some candidates focus so much on what they think the external will ask that they're caught off guard by straightforward questions from the internal.
There's a set of questions that come up in almost every viva. You should have thought through all of them. If you haven't already, work through our list of [50 common viva questions](https://vivacoach.ai/blog/50-common-viva-questions-and-how-to-answer-them) – it covers the ground from opening questions through to curveballs.
But here's the important thing: prepare the thinking, not the words.
Bullet points, not scripts. For each major question, jot down three to five bullet points that capture the key things you want to say. If you write out full answers, you'll either sound robotic when you deliver them or panic when the question comes at a slightly different angle.
Know your thesis inside out. You should be able to explain the argument of any chapter on demand, define any key term without hesitation, and point to the evidence behind any claim. This isn't about memorising page numbers – it's about owning your material.
Prepare for the hard questions. What's the weakest part of your thesis? What would you change? Why didn't you consider a different approach? These questions are coming. If you've already worked through honest answers, they won't catch you off guard.
Have your contribution statement ready. "What is your original contribution?" is the single most important question in any viva. You should be able to answer it clearly, specifically, and confidently in under a minute.
This is the most important section of this guide, and it's the one most candidates skip.
Reading your notes and talking through your defence are completely different cognitive tasks. You can know your thesis perfectly well on paper and still stumble when you have to articulate it verbally under pressure. The only way to bridge that gap is to practise speaking.
Ask your supervisor to run one. Most supervisors will do this as standard, but if yours hasn't offered, ask. A mock viva with your supervisor – or better, with another academic who isn't familiar with your work – is the closest simulation you'll get.
Do more than one. A single mock viva helps, but the real benefit comes from repetition. The first time, you're just getting used to the format. By the second or third, you start to find your rhythm and identify the questions that consistently trip you up.
Record yourself. It's uncomfortable, but listening back reveals habits you won't notice in the moment – filler words, trailing off, spending too long on background before getting to the point.
You don't always need another person. Pick a question, set a timer for two minutes, and answer it out loud. Standing up. No notes. This forces you to organise your thoughts quickly and articulate them clearly.
Do this daily in the two weeks before your viva. Ten minutes a day is enough. Pick five questions at random, answer each one, and move on. You'll be surprised how quickly your confidence builds.
Pay particular attention to transitions – the moments where you move from describing what you did to explaining why it matters, or from acknowledging a limitation to defending your approach despite it. These are the places where candidates most often lose their thread, and they're the places examiners tend to push hardest.
In most vivas, you're allowed – and expected – to have your thesis with you. Practise using it as a reference rather than a crutch. Know where your key arguments, tables, and figures are so you can turn to them quickly when a question calls for specifics. Tabbing or sticky-noting important pages helps enormously. The last thing you want is to spend thirty seconds fumbling through your own thesis looking for a passage you know is in there somewhere.
> This is exactly what VivaCoach is designed for – AI-powered mock viva sessions that adapt to your thesis, challenge your answers with follow-ups, and give you detailed feedback. It's not a replacement for a mock viva with a real academic, but it gives you unlimited practice reps whenever you need them.
Viva formats vary by country, university, and even department. Make sure you know [what to expect](/blog/what-to-expect-in-a-phd-viva-a-guide-to-the-process-the-people-and-the-outcome).
UK vivas are typically private – just you, the internal examiner, the external examiner, and sometimes an independent chair. They usually last one to three hours. Your supervisor may or may not be present, depending on institutional policy, and if they are, they normally can't intervene.
US thesis defenses are often semi-public, with your committee and sometimes an audience. They tend to be more structured, with a presentation followed by questions. The committee will have been involved throughout your PhD, so they already know your work well.
European formats vary widely. Some countries have public defenses with an opponent system, others are closer to the UK model. Check your university's regulations carefully.
Ask someone who's been through it recently. The best source of information about what your viva will be like is a recent graduate from your department. Buy them a coffee and ask: How did it start? How long did it last? What was the atmosphere like? What surprised you?
By this point, your heavy preparation should be done. The last week is about staying sharp without exhausting yourself.
Review your annotations. Go back over the notes you made when you re-read your thesis. Remind yourself of the weak spots and the answers you've prepared for them.
Do a final solo practice session. Run through the big questions one more time: summarise your thesis, state your contribution, explain your methodology, discuss your weakest chapter. If these feel solid, you're ready.
Prepare your materials. Bring a copy of your thesis with your annotations and sticky notes. Some candidates bring a separate notebook with key points, page references, and prepared answers to likely questions. Whatever helps you feel grounded.
Sort the logistics. Know where the room is. Know what time to arrive. If it's online, test your setup. These things sound trivial, but removing uncertainty reduces anxiety.
Stop preparing the night before. Seriously. You will not learn anything new at 11pm that will make a difference. Do something you enjoy, get a decent night's sleep, and trust the work you've put in. Admittedly it is hard – I went to evensong at Christ Church, my Oxford college the night before my viva. It definitely helped soothe my wired brain.
A few things that help:
Arrive early. Give yourself time to settle. Sit in the room if you can. Get comfortable in the space.
Bring water. You'll be talking for one to three hours and your mouth will get dry.
Take your time. You don't have to answer questions immediately. A pause to collect your thoughts is completely normal and signals confidence. Rushing into an answer often leads to rambling. The most important thing is that you answer the questions as robustly as you can.
It's okay to not know everything. If an examiner raises something outside your thesis – a paper you haven't read, a method you didn't consider – don't bluff. Say so honestly, then engage with the idea: "I'm not familiar with that work, but based on my findings, I'd expect..." Examiners respect honesty far more than a half-baked answer. What they won't forgive is not knowing your own research.
Listen to the question. Don't start formulating your answer while they're still talking. If you're not sure what they're asking, ask them to clarify. This is a conversation, not an interrogation.
Remember: most people pass. The vast majority of viva candidates receive their doctorate, often with minor corrections. Your examiners aren't trying to catch you out – they're testing whether you can demonstrate doctoral-level understanding of your own work. If you've written the thesis and done the preparation, you will be more than capable of doing this.
Don't confuse challenge with hostility. Examiners will push back on your claims, question your choices, and play devil's advocate. This isn't a sign that things are going badly. It's a sign that they're engaging seriously with your work. A viva where nobody challenges you would be more concerning.
Use the space. If a question has multiple parts, it's fine to say, "Let me take that in two parts." If you've been talking for a while and aren't sure you've answered the question, ask: "Does that address what you were asking?" These small moves show you're in control of the conversation, not just reacting to it.
Watch your body language. Sit up. Make eye contact. Try not to cross your arms. These things sound superficial, but they affect both how you're perceived and how you feel. Confident posture genuinely helps you think more clearly.
Most candidates receive corrections – minor or major. This is normal. It doesn't mean you failed. It means your examiners want to make your thesis as strong as it can be before it sits on a library shelf forever.
Write down everything while it's fresh. As soon as you leave the room, note the corrections and feedback you were given. Your memory of the specifics will fade quickly, and you'll need clarity when you sit down to make the changes.
Give yourself a break. You've just done something that very few people will ever do. Whatever the outcome, take a moment to acknowledge that fact before you start worrying about corrections.
Six weeks out: Re-read your thesis. Write your one-page summary from memory. Note weaknesses and areas you're unsure about.
Five weeks out: Research your examiners. Read their recent work. Identify areas of overlap and potential challenges.
Four weeks out: Work through common viva questions. Prepare bullet-point answers. Focus on your summary, your contribution, your methodology, your weaknesses.
Three weeks out: Start practising out loud. Solo practice daily. Book a mock viva with your supervisor or a colleague.
Two weeks out: Mock viva. Identify gaps in your preparation. Fill them. Continue daily solo practice.
One week out: Review your annotations. Final practice session. Prepare your materials. Sort logistics.
The day before: Stop. Rest. Do something you enjoy. You've prepared as much as you possibly could.
The day of: I woke up, had breakfast, went to get myself a coffee and rehearsed the answers to all the obvious questions, both in my head and out loud. This made a huge difference when I finally got to the viva.
Want to know what questions to expect? See our [50 common viva questions](/blog/50-common-viva-questions-and-how-to-answer-them).
You wrote the thesis. You did the research. The viva is your chance to show that you understand it, you can defend it, and you're ready to call yourself a doctor.
You've got this.
Ready to start practising? [See our plans](/pricing) and begin your preparation today.