There is no perfect method of examining a PhD thesis and the thesis's author and I appreciate that the Swedish system advocated by David Stephens has many merits (Why I..., 色盒直播S , April 20).
His use of the word "grilled" for the procedure is unfortunate as the process surely requires careful appraisal and not public combat.
The examiner often has to be critical of the supervisor, who may have presented an ill-conceived project or may have made major errors of supervision. Such criticism is better dealt with in private.
An important technical difference between the Swedish method and that used in the United Kingdom is that a thesis in the UK is usually presented in a form that can be corrected, whereas the Swedish system calls for a printed thesis in final form.
It is very helpful to be able to call for either minor corrections or more major ones that allow for re-submission after some months.
Peter Campbell
Department of biochemistry and molecular biology
University College London