A viva is simply an oral exam.

Uses:

The assessment of oral fluency and comprehension e.g. in language learning;

The assessment of personal qualities and attitudes;

The assessment of the ability to think quickly and diagnose problems in novel situations e.g. as a part of medical training;

The further assessment of work previously submitted (e.g. a dissertation, a design, a recording of a musical performance) in order to check that the candidate is the author of the submitted work, to explore particular questions in more depth and to explore understanding further by raising new questions.

Sometimes used where examinees lack writing skills,

Where written responses would be inappropriate (e.g. assessing interpersonal skills),

Where a written test cannot easily be set (e.g. for a student who missed final exams through illness), and

Where further information is required because written assessments have not provided unambiguous information (e.g. for students with "borderline" marks between two degree classifications).

Pros

The flexibility of vivas is their great asset. Issues can be picked up and explored in ways which are seldom possible in written tests with fixed questions which are the same for all students, and in which there is no opportunity to ask supplementary questions in cases of doubt.

Cons

Problems for examiners when using vivas include:

balancing the desire to keep the examinee relaxed with the need to ask challenging questions;

Separating the content of what the examinee has to say from the way in which it is presented.

Turning an overall and fleeing impression gained from a small sample of behaviour into a mark or a clear assessment decision. Very few vivas take very long because they are so expensive in terms of staff time. The vividness of an examiner's impression of a candidate may not be a sound basis for judgement.

Justifying a mark or decision afterwards in the absence of documentary evidence. Defense of viva decisions ion the face of appeals tends to be based on the status and reputation of the examiner rather than on evidence.

Because of the potential problems vivas are often used in conjunction with other assessment methods, for the purpose of increasing the range of information available about an examinee, rather than as a replacement for other assessment methods.

Some examples are:

A viva during laboratory work, to assess students' understanding of what they are doing and encourage them to be thoughtful rather than simply to follow instructions.

A viva as a preparation for other forms of assessment: to identify and diagnose weaknesses which require further attention from the student;