The PhD viva (or viva voce) is often viewed with a mix of dread and anticipation. After years of research, writing, and revisions, it all comes down to a conversation with your examiners to defend your thesis. The viva is a rite of passage in the UK and many other countries, designed to confirm that you are the genuine author of the work and that your contribution meets doctoral standards.

You may have heard horror stories of tricky viva questions, but the reality is that with careful preparation, you can approach your viva with confidence. In this article, we will guide you through the most common viva questions and answers, help you understand what a mock viva is and how useful it can be for a successful viva outcome, and outline strategies for tackling typical PhD viva questions.

What Is a Viva and Why Does It Matter?

A viva voce, Latin for “by live voice,” is an oral examination. In the PhD context, the viva tests your ability to defend and explain your work to experienced academic examiners. Unlike undergraduate or master's defences, the PhD viva expects you to demonstrate an original contribution to knowledge.

Examiners will look for:

  • An in-depth understanding of your thesis
  • Clarity about your methods and their limitations
  • Awareness of the field's literature and your place within it

Some universities also invite or even require you to deliver a short presentation about your research, often with slides. This gives you a chance to frame the discussion on your own terms before the viva questions begin.

Mock Viva: How Useful it Can Be in Your Viva Preparation

One of the best ways to prepare is to hold a mock viva. What is a mock viva, you may ask? Simply put, it is a practice version of the real viva, ideally with experienced academics simulating the question style and intensity of your actual examiners.

It is a rehearsal to test your answers, build confidence, and help identify areas you might overlook under pressure. Mock viva questions mirror the real thing and give you an opportunity to practise thinking aloud about your thesis, so you are less likely to panic on the day.

You might run a mock viva with your supervisors, or with colleagues in your department. Some candidates even record themselves answering typical PhD viva questions to spot gaps in their reasoning or delivery.

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Common Viva Questions and Answers

While every viva is unique, there are certain viva questions that appear again and again. Preparing thoughtful responses will help you navigate these with confidence. Let’s look at some typical PhD viva questions grouped by theme.

Framing and Defining Your Research

Examiners want to understand why you made certain decisions when shaping your topic.

Why did you define the topic in this particular way?
What difficulties did you face while shaping your topic, and did they affect your research direction?
Why did you choose this research question?
How did your ideas about this topic evolve during the research process?

These viva questions help examiners see that you made purposeful, reflective choices about your topic rather than stumbling into it.

How to reply:
Explain the rationale behind your chosen topic. Discuss how gaps in existing research or problems in your discipline led you to define the research question in its current form. It’s helpful to describe briefly how you refined or reshaped your topic as your project progressed. Show confidence in your choices, but be willing to acknowledge practical or conceptual challenges you faced along the way.

Originality and Contribution

The heart of a PhD is its original contribution to knowledge. Expect viva questions such as:

What is original about your thesis?
Where exactly is the novelty in your work?
Which parts of your thesis represent your own distinct contribution?
How do your conclusions develop or take forward the literature in your field?
What are the most innovative aspects of your results?

When answering these, avoid generalities, be precise about how your work differs from and improves upon previous research.

How to reply:
Be clear and explicit about your thesis’s contributions to knowledge. Summarise what is new in your approach, your methods, or your findings. Avoid downplaying your achievements: identify the “bottom line” novelty instead, explain how it differs from past work, and why it matters. Be prepared to talk about whether your findings could be applied beyond the specific case or context you studied.

Impact and Relevance

Alongside your questions, include your research aims and objectives. Your aims are your overall intentions—what you hope the project will achieve. Your objectives are the concrete steps you’ll take to get there. This section can be written as a short paragraph, showing how your questions arise from the context you’ve introduced and how they’ll be answered through your planned approach.

Literature Review

Examiners will also probe the so what? of your work:

What are the “bottom line” conclusions of your research?
How do these conclusions matter in your discipline?
What is the wider relevance of your findings?
What implications do your results have for future research or practice?

Remember to show how your project’s insights could be useful beyond your thesis and, if relevant, discuss to what extent your contributions might generalise to other systems or contexts.

How to answer:
Focus on making your impact crystal clear. Summarise your research findings in straightforward language and explain their significance for your field, practice, or policy. Demonstrate that you understand how your work connects to wider debates or practical issues. Also think about whether your findings might apply beyond the immediate research setting, and be ready to discuss any limitations. A good approach is to have a concise “take-home message” that you can repeat confidently if pressed.

Methodology and Research Design

Methodological rigour is a key pillar of PhD research, and examiners will dig into it:

How well did your study design work in practice?
Did you encounter any problems collecting data?
What were the key ethical issues in conducting your research?
How did you define the limits around your data’s scope?

These viva questions are testing whether you fully understood and justified your choices, rather than simply following a template.

How to reply:
Be honest about any practical difficulties but also show how you addressed them. Examiners value evidence of adaptability and critical reflection on methods. Discuss how you made sure your methodology was robust, how you managed potential bias, and how you handled ethical issues responsibly.

Intellectual Context

You must show you know where your work sits within the broader academic landscape. Be prepared for viva questions like:

How has the field changed since you started your doctorate?
Which propositions are distinctly your own?
You refer only briefly to the field of [X]. Why do you think it is less important than the areas you gave more focus to?
You do not discuss [theory Y] much in your thesis. Why did you decide not to explore it in more detail?

Here, examiners want to see your command of the literature and your ability to explain your choices.

How to answer:
Examiners want to know that you are intellectually grounded. You should be able to map where your research sits within the academic landscape and show how you contribute to advancing knowledge. Be prepared to defend your choices — why you prioritised certain theories or approaches, and why you downplayed others. Show that you are aware of relevant debates, even if they weren’t central to your study. This demonstrates maturity and breadth of scholarship.

Personal Reflection

Typical viva questions that examiners could use as ice-breakers or at the end of the viva:

What did you find most interesting in your research?
How did your thinking develop over the course of the project?
Which part did you enjoy the most, and why?
Were there any surprises?
How has this process changed you as a researcher?

How to answer:
These viva questions give you the opportunity to show your personal engagement and growth. It is perfectly acceptable to talk about how your skills developed, how your confidence grew, or how you became more critical or independent. You could mention surprises that helped you see your topic differently. Showing authentic reflection signals that you learned deeply from the research journey, which is what a PhD is all about.

Specific Challenges

No project is perfect, and examiners know this. These are some common viva questions they could ask about the challenges you faced:

Did you have problems with data collection?
How well did your study design work in practice?
What were the key ethical challenges?
How did you set limits around the data?

How to answer:
Instead of hiding problems, talk openly about them and show you handled them with professionalism. Discuss how you navigated practical, logistical, or even conceptual challenges. Explain why you made particular decisions, how you kept the study robust, and what you would do differently if you repeated it. This kind of reflective honesty is highly valued in a viva.

Key Strategies for Answering PhD Viva Questions

Here are some essential strategies to answer PhD viva questions confidently, demonstrating ownership of your work:

  • Listen carefully. Pause to understand what the examiner is truly asking before replying. It's your moment, so take all the time you need.
  • Structure your answer. One clear argument, supported by evidence from your thesis, is usually best.
  • Admit uncertainties. It is perfectly acceptable to say you do not know or that there are limitations: a confident researcher acknowledges complexity.
  • Refer to your thesis whenever you need to. It is your primary evidence base. Feel free to quote or point to specific pages.
  • Stay calm. You know your work better than anyone, and the examiners want you to succeed.
  • Bring a pen! Do not hesitate to make notes during your viva. These can be extremely useful during the correction phase.

Common Challenges in the PhD Viva

It is completely normal to feel nervous about your viva, but being aware of typical challenges can help:

  • Examiners probe weaknesses. If there is a weak chapter or controversial claim, they will ask about it. Prepare for these.
  • Unexpected tangents. Sometimes you’ll be asked a question that seems only loosely related. Pause, think, and try to link it back to your thesis.
  • Methodological scrutiny. Expect your methodology to be questioned in detail. Justify your choices.
  • Theory gaps. If you left out a certain perspective, have a reason ready for why you did so.

Conclusion

The PhD viva can feel daunting, but remember: it is not designed to catch you out. Examiners want to confirm you are a capable, independent researcher who genuinely owns their contribution to knowledge.

By preparing for common viva questions and answers, rehearsing in a mock viva, and reflecting on your own work, you can face your examiners with confidence and pride. You have earned your place at this stage, now it's just a matter to show them why.

Frequently Asked Questions About PhD Vivas

How do I prepare for my PhD viva?

Read your thesis carefully, practise with mock viva questions, stay up to date with recent research in your field, and get comfortable explaining your work out loud. Mock vivas are particularly valuable for building confidence and identifying gaps in your reasoning. To get an idea of what to expect from your viva and how to prepare, read more about the viva experience of one of our academics.

Are PhD vivas hard?

They can be challenging, but with thorough preparation they are entirely manageable. Examiners want you to succeed, not fail. Being well-prepared and rehearsing common viva questions and answers will help you approach the discussion with confidence.

What should I wear to my viva?

There is no formal dress code for most vivas, but smart-casual attire is generally a good choice. Feeling comfortable yet professional will help you stay confident.

How long does a PhD viva take?

A typical viva can last between 90 minutes and 2 hours, depending on how many viva questions the examiners have and how detailed the discussion becomes.

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