The viva voce, or oral examination, is the final stage of most PhD journeys. For many candidates, the methodology section of the viva feels the most intimidating. Examiners may ask why you chose your approach, why you did not use another method, how you selected participants, how you ensured rigour, and what you would do differently. These questions test not only what you did, but whether you understand why you did it.
The good news is that methodology questions are highly predictable, and you can prepare for them systematically. This post explains what examiners are looking for, the most common types of methodology questions, how to prepare strong answers, and how to handle difficult questions calmly.
What examiners want to see
In the methodology part of the viva, examiners generally want to confirm that you:
- Understand your research design and can explain it clearly.
- Made deliberate, justified choices rather than following a template.
- Know the alternatives and can explain why you did not choose them.
- Recognise the limitations of your approach and their impact on your findings.
- Can defend your work without becoming defensive.
- Have grown as a researcher and can reflect on what you would do differently.
Examiners do not expect a perfect study. No study is perfect. They expect you to understand your study's strengths and weaknesses and to discuss them honestly and thoughtfully.
Common methodology questions
Philosophy and overall approach
- What is your research philosophy or paradigm, and how did it shape your study?
- Why did you choose a quantitative, qualitative or mixed methods approach?
- How does your methodology fit your research questions?
Research design
- Why did you choose this design (survey, case study, experiment, grounded theory, etc.)?
- What alternative designs did you consider, and why did you reject them?
- Why is your study cross-sectional rather than longitudinal?
Sampling and participants
- How did you define your population?
- Why did you use this sampling method?
- How did you decide on your sample size?
- How representative is your sample? Who might be missing?
- How did you know when to stop collecting qualitative data?
Data collection and instruments
- Why did you choose these instruments or scales?
- How did you establish validity and reliability?
- Did you pilot your instrument? What changed as a result?
- How did you design your interview guide?
- How might your presence as a researcher have influenced the data?
Data analysis
- Why did you choose this analysis technique?
- How did you check the assumptions of your statistical tests?
- How did you handle missing data and outliers?
- Can you explain what this coefficient or fit index means?
- How did you develop your themes? Can you show an example of your coding?
Rigour, ethics and limitations
- How did you ensure the trustworthiness or validity of your findings?
- What ethical issues did you face, and how did you address them?
- What are the main limitations of your methodology?
- How do these limitations affect your conclusions?
- If you started again, what would you do differently?
How to prepare
1. Re-read your thesis carefully
Some time will usually have passed between submission and the viva. Read your whole thesis again, especially the methodology chapter. Mark key decisions, justifications and any errors or unclear sections you notice. It is better to find typos or inconsistencies yourself and acknowledge them than to be surprised by them in the viva.
2. Create a methodology summary sheet
Prepare a one- or two-page summary of your methodology covering:
- Research questions.
- Philosophical position.
- Design and rationale.
- Sampling strategy, sample size and justification.
- Instruments and their validity and reliability.
- Analysis methods and why they were chosen.
- Key ethical considerations.
- Main limitations.
Writing this summary helps you see the logic of your design as a whole.
3. Prepare “why” answers for every major decision
For each decision, prepare a short answer that includes:
- What you did.
- Why you did it, linked to your research questions, theory or practical considerations.
- What alternatives you considered.
- Why you chose this option over the alternatives.
- What limitations this choice brings.
For example: “I used a cross-sectional survey because my research questions focused on relationships between variables across a large population of employees, and a survey allowed me to reach over 300 participants across several organisations. I considered a longitudinal design, which would have strengthened causal inference, but access to organisations was only possible for one data collection period. As a result, I cannot establish the direction of relationships, which I discuss as a limitation in Section 6.4.”
4. Know your key methodological references
Be ready to name and briefly explain the main sources that underpin your methodology, such as the authors of your analytic approach, sampling guidance or quality criteria. You do not need to memorise page numbers, but you should know why you cited them.
5. Understand your analysis deeply
If you used statistics, be able to explain in plain language what your main tests do, what the key numbers mean, and why the assumptions matter. If you used qualitative analysis, be ready to show how a quote became a code, how codes became themes, and how you ensured rigour. Bring or mark examples in your thesis.
6. Prepare an honest limitations narrative
Examiners almost always ask about limitations. Prepare two or three main limitations, explain their impact on your findings, what you did to reduce them, and how future research could address them. Present limitations as signs of critical awareness, not as confessions of failure.
7. Practise with mock vivas
Ask your supervisor, colleagues or a research development office to hold a mock viva. Practising aloud is very different from preparing in your head. Ask your mock examiners to challenge your methodological choices. Record yourself if possible, and review where your answers were unclear or too long.
8. Stay updated
If important new studies or methodological developments have appeared since submission, be aware of them. Examiners may ask how recent work relates to yours.
Sample answers to three common questions
Here are illustrative examples of how you might structure answers. Adapt them to your own study.
“Why did you choose a qualitative approach?”
“My research question asked how first-generation doctoral students make sense of academic culture. Because the aim was to understand experiences and meanings rather than measure frequencies or test relationships, a qualitative approach was the best fit. Semi-structured interviews allowed participants to describe their experiences in their own words, and reflexive thematic analysis allowed me to interpret patterns of meaning across accounts. A survey could have reached more people, but it would not have captured the depth and nuance I needed. The trade-off is that my findings are not statistically generalisable, so I focus on transferability through detailed description of the context.”
“How did you decide on your sample size?”
“For the quantitative phase, I conducted an a priori power analysis in G*Power, which indicated a minimum of 92 participants to detect a medium effect in my regression model. I aimed for more to allow for incomplete responses and achieved 214 usable responses. For the interviews, I did not set a fixed number in advance; I analysed interviews as I went and stopped when additional interviews were no longer adding new codes relevant to my research questions, which happened at around 18 interviews. I documented this in the code-tracking table in Appendix F.”
“What is the main limitation of your study?”
“The main limitation is that the survey was cross-sectional and all variables were self-reported. This means I cannot establish causal direction, and some relationships may be inflated by common method variance. I tried to reduce this by separating constructs in the questionnaire, assuring anonymity and testing for common method bias, and I have avoided causal language in the discussion. A longitudinal design with multi-source data would be a valuable next step.”
Notice that each answer links back to the research question, explains the decision, names alternatives or trade-offs, and refers to evidence in the thesis. This structure works for almost any methodology question.
How to answer difficult questions
Take your time
It is acceptable to pause, think, and ask for a question to be repeated or clarified. A short pause often leads to a clearer answer.
Acknowledge valid criticism
If an examiner points out a genuine weakness, acknowledge it. Then explain the reasons behind your decision and discuss how it affects your conclusions. For example: “That's a fair point. With hindsight, a larger sample from rural schools would have strengthened the findings. At the time, access was limited because... In the thesis I have been careful to limit my conclusions to urban schools.”
Defend without being defensive
If you believe your choice was justified, explain your reasoning confidently and politely, with reference to your research questions and the literature. The viva is an academic conversation, not an attack.
Be honest if you do not know
If you are asked about something you genuinely do not know, say so and, if possible, explain how you would find out or reason through it. Guessing or bluffing is usually obvious and less convincing than honesty.
Show reflection
When asked what you would do differently, give a thoughtful answer. This shows maturity and independence as a researcher, which is exactly what a PhD aims to develop.
Common mistakes to avoid
- Memorising textbook definitions without linking them to your own study.
- Being unable to explain why alternative methods were not chosen.
- Denying obvious limitations.
- Giving very long answers that drift from the question.
- Becoming defensive or dismissive of examiner concerns.
- Not knowing your own thesis well enough to find key sections quickly.
Final thoughts
Methodology questions in the viva are an opportunity to show that you are an independent researcher who understands and can justify your work. Prepare by re-reading your thesis, summarising your methodology, preparing “why” answers for every major decision, understanding your analysis deeply, and practising aloud. Approach difficult questions calmly and honestly. Remember that examiners are not looking for a perfect study; they are looking for a thoughtful researcher. With good preparation, you can walk into your viva confident that you can explain and defend every step of your research.
Is your viva coming up? Share the methodology question you are most worried about in the comments, and we will help you prepare an answer.