What Happens at a PhD Viva

The format

A UK PhD viva is an oral examination with two examiners: one internal, from your institution, and one external, from another university. Sometimes a third examiner or an independent chair is present, but they do not typically question you.

You sit at a table with both examiners. No audience. You can bring an annotated copy of your thesis, notes, and anything else your institution permits. Check your regulations before the day.

Duration varies by discipline and examiner style. Most vivas run between ninety minutes and three hours. A short viva is not a bad sign. A long one is not a good one.

How the session begins

The external examiner typically leads. They will often open with something broad: "Can you summarise your thesis and explain what it contributes?" That question is not a warm-up. It is the first real test of whether you understand your own work at the level of the discipline.

Answer directly. Name the contribution before you describe the chapters. Most candidates describe the chapters first and reach the contribution fifteen minutes later. Examiners notice this.

The arc of questioning

Questions move through your thesis in a roughly predictable sequence: contribution and positioning, theoretical framework, methodology and analytical choices, findings and their limits, implications. The exact order varies, but those areas are consistent across disciplines.

Early questions tend to be broad. Later ones get specific. The examiner is watching whether your answers become more precise as the session goes on, or whether they thin out under sustained questioning.

Follow-up questions are the core diagnostic. If your first answer is thin, the examiner will press. Defend your reasoning under follow-up and the session moves forward. Fail to do that and the same ground will be revisited.

What examiners are deciding

Examiners are not trying to catch you out. They are assessing whether you understand your work at doctoral level: whether you can locate it within the discipline, defend the choices you made, and speak honestly about its limits.

The most common reason candidates struggle is not a weak thesis. It is that they cannot articulate why they made the decisions they made. Examiners probe for reasoning, not description.

The outcome

At the end of the viva, the examiners ask you to leave while they deliberate. They call you back and give their recommendation. The most common outcomes are: pass with minor corrections, pass with major corrections, and referral for resubmission. Outright failure at viva is rare for candidates whose supervisors recommended them for submission.

Minor corrections usually mean small textual changes, typographical errors, or clarifications. You will usually have up to three months to complete them, though some institutions allow longer. Major corrections mean substantive revisions to argument, analysis, or structure. These typically come with a six to twelve month window.