The examination of PhDs is a curious business. In many ways, the viva is as much an examination of the supervisor as it is of the student – at least in the sciences. When a student gets to the viva stage, we can assume that the supervisor is generally happy with the quality of the work and has confidence in the abilities of the student. It would be negligent for the supervisor to think otherwise because failing a viva is a catastrophic event for any young person. But some supervisors put a huge amount of work into the thesis and make sure that it is ‘immaculate’ at the viva stage. Others take a more laissez faire approach, viewing the thesis as being the student’s business. In this case, the result can be a very sloppy and amateurish thesis, something I have seen a couple of times recently.
But what if the examiners have some fundamental disagreement with the basic tenets of the work? Then, it all gets messy, even if the student performs well in the viva and the thesis is well written. In many ways, this is now a dispute between the supervisor and the examiner(s) and the student is caught in the middle. I’m not sure if there are any formal procedures for dealing with this kind of situation.
Indeed, this inextricable link between the student and the supervisor is fundamental to the whole PhD process. We tend to think of the PhD as a sort of research apprenticeship, i.e., we think in terms of its educational role. But ‘producing’ PhDs is very much part of the academic’s career. Indeed, producing PhDs, writing papers and acquiring grant income are three of essential ingredients required for academic promotion. Therefore, it is very much in the interest of the academic to recruit PhD students, to ensure that they graduate as quickly as possible and to design the project so that as many papers as possible are produced from the work.
But, this can lead to the recruitment of people whose ability to complete a PhD may be marginal – I’ve seen a few examples of this in recent years. Of course, this will rarely be a problem for the top tier of researchers; those in the ‘Premiership’ who have well-resourced, internationally-ranked laboratories and who always attract the best students. Problems with marginal students occur for those of us down in the ‘Championship’.
There may also be a tendency to construct the PhD thesis as a selection of problems that will yield papers rather than as a coherent body of important work. The concept of the LPU or ‘least publishable unit’ will be familiar to many. This can result in many problems ‘left hanging’ as the student moves on to the next problem in search of another publishable unit. The result can be a pretty superficial thesis, albeit one that is backed up by a number of publications. In recent theses I have read, I have found that instead of ‘staying put’ and really drilling down into a problem, the student has packed up and left to pursue a new one. It is frustrating because many times it seems that the student has moved on just as the problem is getting interesting. It’s as if the student and supervisor are not really trying to solve problems but making enough progress on the problem to ‘generate a paper’.
The whole process is complicated by the fact that the student’s PhD is typically funded by some external agency and it will be expected that certain project objectives will be met, even if that conflicts with a more purist scientific approach.
Inevitably, therefore, the coupling between the educational needs of the student, the career needs of the academic and the requirement to meet certain project objectives means that assessing PhDs can be pretty problematic. It’s certainly not an exact science.