Viva voce is Latin for "with the living voice". In practice it means an examination where a student answers questions out loud, in real time, from an examiner who can follow up. That last part is the whole thing. A question you cannot follow up on is a quiz. A question you can follow up on is an examination.
Where you still find one
The format is often described as old-fashioned, which is odd given where it is still mandatory. A doctoral candidate defends a thesis. A medical student is examined at a bedside on a patient they have just assessed. Bar and licensing boards in many countries include an oral component. Language certification is oral almost by definition, because speaking is the thing being certified.
These are the settings where being wrong about a person's competence is expensive. That is not a coincidence, and it is the strongest available argument for the format.
What makes one good
Most complaints about oral exams are complaints about badly run ones. The research on this is fairly consistent: structure is what separates a reliable oral exam from a stressful lottery.
- Questions grounded in something specific the candidate produced, rather than general knowledge probing.
- A rubric written before the exam, so the examiner is scoring against criteria rather than against their mood.
- Comparable coverage across candidates. Everyone gets pushed on roughly the same kinds of thing.
- Follow-ups that go deeper rather than sideways. "Why did you choose that" beats "tell me another example".
- A record. Anything with consequences should be reviewable.
An unstructured oral exam measures confidence. A structured one measures understanding. The format gets blamed for the difference.
The honest weakness
Oral examination is expensive in the only currency schools genuinely lack, which is examiner time. One examiner, fifteen minutes, three hundred students: that is seventy five hours before anyone marks anything. This is why the format retreated to the places that could afford it, and it is the entire reason most undergraduates never sit one.
It is also the constraint that has changed most in the last three years, which is why the question is live again. We wrote about that shift in the oldest exam in the world is coming back.