How to Prepare for a Viva

Prepare to explain your work in a viva

A viva asks you to explain a topic or project aloud and respond to follow-up questions. Memorising a long opening speech is not enough: an examiner may interrupt, ask why you chose a method, or change an assumption. Prepare around the work you actually did and the limits of what it shows.

Create a question map from your own material

For a project, list the problem, objective, method, important observations, conclusion and limitations. Add “why?” beside each choice. Why did you use that sample? Why that equation, tool or measurement range? Which variable was controlled? What would make the result unreliable? For a practical subject, include instrument names, units, setup steps and the meaning of important readings.

Practise a compact answer structure

Start with a direct answer, give the reason, then connect it to evidence. If asked why repeated measurements were taken, explain that they help reveal variation, describe how you recorded them, and distinguish random variation from a consistent instrument offset. Repetition alone does not remove a systematic error. Use a diagram or calculation when words leave an important relationship unclear.

A sample project exchange

Question: What does your survey tell us about students' study habits? Answer: It describes the responses from the students who completed our questionnaire. We compared reported study time across the respondents, but cannot infer that the same pattern represents every student. Follow-up: Why not? Reason: The sample came from one class and participation was voluntary. This answer shows an understanding of scope without inventing stronger evidence.

Use a mock viva with real follow-up questions

1. Give a one-minute overview without reading slides.
2. Ask a friend to select a diagram, table or method and request an explanation.
3. Let them ask one unexpected follow-up question.
4. Record where you became vague, used an undefined term or contradicted your report.
5. Return to the material, correct the explanation and practise it again.

A phone recording can reveal rushed delivery or a habit of speaking before understanding the question. Use recordings for your own preparation and get permission before recording anyone else.

When you do not know an answer

Pause, ask for clarification if the question is ambiguous, and separate what you know from what you are unsure about. You may explain a relevant principle or the next step you would use to investigate. Do not invent a reading, source or experiment. If the examiner points out an error, acknowledge the specific correction and revise the reasoning.

Before the day, check the official instructions for duration, permitted materials, report copies and attendance. Organise diagrams and data so you can locate them quickly. Preparation should make you more accurate and responsive, rather than train you to recite an answer regardless of the question.