A mock viva is a practice oral examination that rehearses the PhD viva voce before the real examination. You answer the kinds of questions examiners ask — about methodology, contribution, limitations, and significance — under conditions as close to the real exam as you can manage. The purpose is to find where your spoken defence breaks down while there is still time to fix it.

How do you run a mock viva?

The simplest version is one person asking you questions while you answer without notes. A better version sets a time, a room, and a sequence that mirrors the real examination — an opening summary, methodological questions, contribution questions, limitations, and at least one question you were not prepared for. The person running it should be briefed to follow up rather than accept the first answer. Record it if you can.

Is a mock viva worth it?

Yes, with one qualification: a mock that only covers comfortable ground is not worth much. The value comes from hearing yourself stumble on a question you thought you knew the answer to, before the real examination. Most candidates are more fluent on paper than in person. A mock makes the gap visible while it can still be closed.

Who should run my mock viva?

Your supervisor is the highest-value option — they know your thesis, your institution, and often your examiners. The limit is that supervisors tend to be gentler than actual external examiners. Peers are useful early in preparation. An AI committee is useful for content drilling at any hour, without social cost, and can be repeated as many times as you need. Ideally you use more than one option.

How many mock vivas should I do?

More than one. A single mock produces a list of gaps. A second mock tests whether those gaps closed. For AI sessions, five to ten in the weeks before the exam is common among well-prepared candidates. For human mocks with a supervisor or colleagues, one or two is typically realistic given the scheduling constraints. The constraint is not what is sufficient — it is what is achievable.

What questions are asked in a mock viva?

The same questions your actual examiners will ask: 'Summarise your thesis.' 'What is your original contribution?' 'Why did you choose this methodology?' 'What would you do differently?' 'How does your work relate to X?' And at least one question that does not have an obvious answer. A mock that only asks questions you have prepared for is missing the point. The unprepared question is part of what the mock is for.

Guide

What Is a Mock Viva?

A mock viva is a practice oral examination that rehearses the real viva voce or dissertation defense before it happens. You answer the same kinds of questions examiners ask — about your methodology, your contribution, your limitations — under something resembling exam conditions. The goal is to hear yourself think out loud and find where your answers break down, before it matters.

Last updated June 13, 2026

What a mock viva is and what it is not

A mock viva is not a formality. It is not your supervisor reading back your abstract and telling you it looks fine. At its most useful, it is an uninterrupted hour or more in which someone — a person or an AI committee — asks you the questions your examiners are likely to ask and follows up when your answer is vague, incomplete, or internally inconsistent.

The viva voce (literally 'by living voice') is the oral examination standard in UK and European doctorate programs. US candidates defend rather than viva — the format includes a public presentation and a larger committee, but the substantive questioning is the same exercise. In both cases, the purpose of the mock is identical: surface the gaps in your spoken defence before the real examination begins.

Most candidates are more fluent on paper than in person. Reading a chapter you wrote is not the same as defending a methodological choice under follow-up from someone who has read the same literature you have. A mock viva makes this gap visible while there is still time to close it.

What a mock viva should actually rehearse

A mock that only covers the questions you feel confident about is not a mock — it is a highlight reel. The questions worth drilling are the ones that make you hesitate. These tend to cluster around a predictable set of areas.

Opening summary: 'Can you summarise your thesis in two to three minutes?' Most candidates are not prepared for this. It is often the first question and an unprepared answer sets a difficult tone for everything that follows.
Contribution and significance: 'What is the original contribution of this thesis?' and 'Why does it matter?' Examiners want a direct claim, not a tour of the literature. Candidates who hedge here, or who describe the process rather than the result, tend to get followed up on hard.
Methodology justification: 'Why did you choose this method rather than X?' Not just a description of what you did, but a defence of why — and an honest account of what the chosen method cannot do.
Limitations: 'What would you do differently?' Examiners are not fishing for a confession of failure. They want evidence that you can think critically about your own work. Candidates who minimise limitations or who have not thought about them in advance tend to struggle here.
Handling a question you cannot answer: Every viva contains at least one question you did not prepare for. The mock should include some. The skill is not knowing the answer; it is knowing how to handle not knowing it.
Situating your work in the field: 'How does your thesis relate to X's argument?' You need to be able to place your work in relation to the key scholars and debates in your area, not just describe your own chapters.

These are not exhaustive, but a mock that covers all six of these areas will surface most of the places where preparation is needed.

Three ways to run a mock viva

There are three realistic options. Each has a genuine use and a genuine limit.

With your supervisor or advisor

This is the highest-value mock available to most candidates, for specific reasons. Your supervisor knows your thesis, knows your institution, and often knows your examiners — their views, their known methodological preferences, any published criticism of approaches like yours. That contextual knowledge is not available anywhere else. The limit is equally specific: supervisors want their students to pass, and that instinct can soften the examination. A supervisor who feels uncomfortable asking a question that might upset you before a high-stakes exam is a normal human being, not a bad supervisor. It means their mock is likely to be less adversarial than the actual viva.

With peers or labmates

More available and easier to schedule than a supervisor mock, and useful for the basic exercise of saying things out loud in front of another person. The limit is that peers pull punches more than supervisors do. A labmate who is also your friend is unlikely to pursue a line of questioning that visibly distresses you. They also may not know your subfield well enough to ask the question your external examiner considers basic. Peer mocks are better than no mock, and they are most useful early in preparation when you are still working out how to articulate things at all.

With an AI examining committee

An AI committee is available at any hour, costs nothing per session, and has no prior relationship with you to protect. It does not soften questions because it feels awkward. The limits are direct: it does not know your specific examiners, it cannot see you, it cannot replicate the social pressure of a physical room, and it works only from what you describe about your work. MockDefense uses a three-member committee — Chair, Methodologist, and Outside Examiner — designed to reflect the different angles a real examining panel covers. The outside examiner role in particular is designed to ask the question your supervisor would feel uncomfortable asking. Start with a free drill; no card required.

What a mock viva cannot do

A mock viva, however good, does not replicate the actual examination. The specific people who will sit across from you, the specific questions they have prepared, the specific room, the silence before an answer — none of these can be reproduced in advance.

This does not mean mock practice is limited in value. It means the value is specific: fluency on content, familiarity with the structure of the examination, and practice at handling uncertainty. These things transfer. The social dynamics of the specific room do not transfer, but exposure to a mock at all — any mock — reduces the shock of the real thing.

The other honest limit: most candidates who reach the examination stage pass. The UK viva pass rate is high; most candidates are awarded their degree, usually with minor corrections. A mock viva is not preparation for failure — it is preparation for performing well in a high-stakes, unfamiliar format.

How to get more from a mock viva

Most of the value of a mock comes from what happens after it, not during it. A session that runs and produces no notes is most of the work wasted.

Record it if possible. Watching yourself answer under pressure reveals things you do not notice in the moment — filler phrases, long pauses, hedging language, trailing sentences. Most candidates are surprised by what they see.
Do more than one. A single mock viva, however good, produces a list of gaps. A second mock — ideally after you have worked on those gaps — tests whether they have actually closed. One mock is better than nothing; several mocks are better than one.
Target your weakest areas. A full mock covering everything is useful once. After that, focused sessions on the two or three questions you fumble are more efficient than running the whole arc again.
Simulate the pressure as much as you can. Dress as you plan to dress for the exam. Sit at a desk rather than a sofa. Answer without notes in front of you. The conditions matter more than most candidates expect, because the physical habits you practise are the ones that will be available to you on the day.
Tell your mock examiner explicitly to follow up. The follow-up question — 'What do you mean by that exactly?' or 'Why not method X instead?' — is where most answers either hold or fall apart. A mock that only asks the headline question and accepts whatever you say is not preparing you for an examiner who pursues.

When to schedule your mock viva

As early as you can bear. Most candidates wait until they feel ready, which typically means waiting until there is not enough time to act on what the mock reveals.

A reasonable sequence: start AI practice sessions as soon as you have submitted or know your submission date — use them to build content fluency chapter by chapter. Schedule your supervisor mock for two to three weeks before the exam, when your answers on content are already solid and the mock can focus on harder questions. After the supervisor mock, return to AI sessions for the specific gaps it revealed.

If you have access to a full AI committee across multiple sessions, a monthly plan or the $49 90-day Defense Pass covers the period from submission to exam without having to ration sessions.

Frequently asked questions

What is a mock viva?: A mock viva is a practice oral examination that rehearses the PhD viva voce before the real examination. You answer the kinds of questions examiners ask — about methodology, contribution, limitations, and significance — under conditions as close to the real exam as you can manage. The purpose is to find where your spoken defence breaks down while there is still time to fix it.
How do you run a mock viva?: The simplest version is one person asking you questions while you answer without notes. A better version sets a time, a room, and a sequence that mirrors the real examination — an opening summary, methodological questions, contribution questions, limitations, and at least one question you were not prepared for. The person running it should be briefed to follow up rather than accept the first answer. Record it if you can.
Is a mock viva worth it?: Yes, with one qualification: a mock that only covers comfortable ground is not worth much. The value comes from hearing yourself stumble on a question you thought you knew the answer to, before the real examination. Most candidates are more fluent on paper than in person. A mock makes the gap visible while it can still be closed.
Who should run my mock viva?: Your supervisor is the highest-value option — they know your thesis, your institution, and often your examiners. The limit is that supervisors tend to be gentler than actual external examiners. Peers are useful early in preparation. An AI committee is useful for content drilling at any hour, without social cost, and can be repeated as many times as you need. Ideally you use more than one option.
How many mock vivas should I do?: More than one. A single mock produces a list of gaps. A second mock tests whether those gaps closed. For AI sessions, five to ten in the weeks before the exam is common among well-prepared candidates. For human mocks with a supervisor or colleagues, one or two is typically realistic given the scheduling constraints. The constraint is not what is sufficient — it is what is achievable.
What questions are asked in a mock viva?: The same questions your actual examiners will ask: 'Summarise your thesis.' 'What is your original contribution?' 'Why did you choose this methodology?' 'What would you do differently?' 'How does your work relate to X?' And at least one question that does not have an obvious answer. A mock that only asks questions you have prepared for is missing the point. The unprepared question is part of what the mock is for.

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MockDefense builds AI examiners that rehearse the questions a real doctoral committee asks — on methodology, contribution, and the gaps you haven't patched yet. Our guides are written from that examiner's-eye view of what defenses actually test.

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