A viva voce, more commonly referred to as ‘viva’, is an oral examination conducted at the end of your PhD and is essentially the final hurdle on the path to a doctorate. It is the period in which a student’s knowledge and work are evaluated by independent examiners.
In order to assess the student and their work around their research question, a viva sets out to determine:
Note: A viva is a compulsory procedure for all PhD students, with the only exception being when a PhD is obtained through publication as opposed to the conventional route of study.
In the UK, at least two examiners must take part in all vivas. Although you could have more than two examiners, most will not in an attempt to facilitate a smoother questioning process.
One of the two examiners will be internal, i.e. from your university, and the other will be external, i.e. from another university. Regardless, both will be knowledgeable in your research field and have read your thesis beforehand.
In addition to your two examiners, two other people may be present. The first is a chairperson. This is an individual who will be responsible for monitoring the interview and for ensuring proper conduct is followed at all times. The need for an external chairperson will vary between universities, as one of the examiners can also take on this role. The second is your supervisor, whose attendance is decided upon by you in agreement with your examiners. If your supervisor attends, they are prohibited from asking questions or from influencing the outcome of the viva.
To avoid any misunderstandings, we have summarised the above in a table:
| Individual | Mandatory or Optional? | Presence decided by? | Can Ask Questions and Impacts Outcome? |
| Examiners | Mandatory and minimum of 2 | Your supervisor | Yes |
| Chairperson | Optional | Your university | No |
| Your Supervisor | Optional | You, in agreement of both examiners | No |
Note: In some countries, such as in the United States, a viva is known as a ‘PhD defense’ and is performed publicly in front of a panel or board of examiners and an open audience. In these situations, the student presents their work in the form of a lecture and then faces questions from the examiners and audience which almost acts as a critical appraisal.
Since all universities have different guidelines, and since all PhDs are unique, there are no standard durations. Typically, however, the duration ranges from one to three hours, with most lasting approximately two hours.
Your examiners will also influence the duration of your viva as some will favour a lengthy discussion, while others may not. Usually, your university will consult your examiners in advance and notify you of the likely duration closer to the day of your viva.
Regardless of the subject area, all PhD vivas follow the same examination process format as below.
You will introduce yourselves to each other, with the internal examiner normally introducing the external examiner. If an external chairperson is present, they too are introduced; otherwise, this role will be assumed by one of the examiners.
After the introductions, the appointed chair will explain the viva process. Although it should already be known to everyone, it will be repeated to ensure the viva remains on track during the forthcoming discussion.
The examiners will then begin the questioning process. This usually starts with a few simple opening questions, such as asking you to summarise your PhD thesis and what motivated you to carry out the research project.
The viva questions will then naturally increase in difficulty as the examiners go further into the details of your thesis. These may include questions such as “What was the most critical decision you made when determining your research methodology?”, “Do your findings agree with the current published work?” and “How do your findings impact existing theories or literature?”. In addition to asking open-ended questions, they will also ask specific questions about the methodology, results and analysis on which your thesis is based.
Once the examiners are satisfied that they have thoroughly evaluated your knowledge and thesis, they will invite you to ask any questions you may have, and then bring the oral examination to a close.
Once your viva has officially ended, your examiners will ask you to leave the room so that they can discuss your performance. Once a mutual agreement has been reached, which can take anywhere from 10 minutes to an hour, you will be invited back inside and informed of your outcome.
There are six possible outcomes to a viva: