Ewan Gillon's assertion (THES, February 20) that the viva is purely a traditional torture for graduate students conveniently ignores some of the essential elements of the PhD. The very essence of a thesis is that it offers a proposition that is argued in the dissertation and subsequently defended by the candidate. In addition to the need to confirm that the candidate who presents him or herself for examination is, indeed, the author of the thesis, the examiners give the student an opportunity to defend the thesis in front of experts in the subject.
It has been argued that the PhD viva is "soft" and that we should follow the example of many other European universities and require a public defence of a PhD thesis.
Anyone who has conducted a PhD examination will be aware that the university authorities require written justification of the outcome; a referral or outright failure will only be accepted if a cogently argued case is made by the examiners. Most universities have an appeals procedure and, in cases of any doubt, the first action is usually the appointment of an additional external examiner.
Many of us will have experienced students who rejoiced immediately after an easy viva but on later reflection felt cheated of an opportunity to offer a more comprehensive defence of their work. It is very important that we maintain the rigour with which the PhD is assessed and it would be wrong to abolish the viva, which has proven very effective, on the flimsy basis argued by Ewan Gillon.
Roger D. Pollard. School of electronic and electrical engineering, University of Leeds