Nasty PhD Viva Questions

Dr. Andrew Broad

A PhD candidate needs to anticipate the questions that are likely to be asked in the viva - the "horrible ordeal where you have to defend your thesis in person before they rip you to shreds." Actually, it's not nearly as bad as it sounds, provided that you enter it having prepared to your utmost.

There are three reasons why PhD candidates have to have a viva: it is so the examiners can see:


whether it is your own work;
whether you understand what you did;
whether it is worth a PhD (i.e. is a contribution to knowledge).

These are the points being examined (according to Alex Gray from the University of Cardiff):


Understanding: that you're ready to become an independent researcher.
Relationship to other work: that you have a command of your subject-area. Similarity to the work of others doesn't detract from novelty!
Novelty - is your work publishable? If you have already published a couple of papers, that should be proof of sufficient originality. Don't panic about recent publications that are very similar to your work - the important thing is to be aware of them, and to know the differences between your work and theirs.
What you have achieved, and that you are aware of its implications. What will it make a difference to?

Demonstration of hypothesis (what you set out to achieve). How have you evaluated/tested your hypothesis? Always be prepared to reconsider your hypothesis if you end up demonstrating something else - it's vitally important that your results match your hypothesis, and that you have a convincing argument for this.
Why did you do it the way you did? Not just your practical work, but everything. For example, your literature review should be focused towards your hypothesis.