Oral examinations also referred to as viva voce, have been used by universities to evaluate students’ learning for centuries. The exam takes the form of a ‘conversation between master and pupil’. However, due to the low objectivity associated with this approach to evaluation and the staff time needed to conduct such examinations, its use has become less frequent in recent times. At some universities it is now no longer used in undergraduate education and is only found in the defence of a doctoral or master’s dissertation.
Oral exams test students’ reasoning and communication skills, including their use of scientific language and can be used as an additional “test” to probe whether the results obtained in written examination were a fair reflection of the candidates understanding or not. Here, the role is primarily one of validation rather than assessment. This remains common practice in the UK, where external examiners routinely hold oral exams for borderline candidates in bachelor programmes. An oral exam can also help to reduce the risk of making an award to a candidate who has had his/her thesis written by a third party. The examiner’s task in an oral exam is to provoke thought and assess the depth of understanding. A written test is likely to be much more efficient for evaluating the basic knowledge of a candidate. Oral exams can also be a useful learning tool, especially when students are initially asked for some self-evaluation and are provided with detailed feed-back at the end. It is particularly important to identify clear assessment criteria before embarking on any oral evaluation (see for example). https://assessment.trinity.duke.edu/documents/OralExamEvaluationCriteria1.pdf )
Proper conduct of an oral exam requires:
An oral exam can be offered as an alternative to a written assessment for students with learning disabilities, such as: dysgraphia, non-verbal learning disorder etc.
Even the best prepared and conducted oral exam is likely to be less objective than a written one, with the mark obtained being influenced by a number of effects (e. g. the halo effect http://en.wikipedia.org/wiki/Halo_effect ) and it may also be impacted by the student’s appearance, behaviour, gender, ethnicity and visible disability.