Last Wednesday I attended a PhD defense in Tohoku University at the department of physics, as one of the examiners. The candidate has been working with a German Professor with whom I have been collaborating in these years. And his supervisor is one of my past colleagues. Due to this situation, the supervisor asked me to join the examination. The examination was successful according to my observation. (I still have some issues for further discussion but it is just natural for scientific works.) After finishing the event, the supervisor and the other professor kindly invited me to late lunch and I enjoyed very nice sea foods. I appreciate their kind consideration. Owing to the new subway line, the campuses of Tohoku Univ are now in very good connections to the main station of Sendai. Because I did not have sufficient time for discussion with the researchers there, I wish to visit there in near future.
I am rather interested in the differences in phD defense, although it is problematic to disclose the details of evaluation procedure here.
Nevertheless, for Japanese universities to which I have belonged including Nagoya and Kyoto, phD defense is typically for a couple of hours including discussion. Most of the cases, before the defense a pre-screening takes place in which the candidate makes presentation for the core members of examiners, and the phD defense is set with the approval of the examiners. Usually the pre-screening is rather tough and it takes several hours due to detailed discussions for the phD thesis which has to be submitted to the examiners in prior to the event. The supervisor of the candidate is usually involved in the examiners. These basic construction seems common for Japanese universities.
On the other hand, the construction of phD defense is different for foreign universities. For instance, I was invited to be an examiner of phD for the department of math in the Univ. Reading, UK. At that time, the candidate did not make any oral presentation. Instead, the examiners and the candidate shared a table to discuss the contents of thesis with a page to page manner. The event was quite tough for both sides, and actually it takes 4-5 hours. Interestingly, the supervisor cannot be involved in the evaluation, and he did not attend the event. Further interestingly, the chair of examiners seems necessarily invited from outside and actually I was the chair in that particular occasion. One of my friends in Brazil told me that the Brazilian universities make a similar phD defense. In UK, invitation of reviewers outside seem also mandatory for the evaluation of promotion for faculty members.
Personally, I prefer to have an oral examination to grasp the whole story of thesis which is usually more than 100 pages, and some cases the contents are not close to my own research field. On the other hand, a page-to-page reading of thesis with the candidate is a strict way for evaluation of phD degree. In such a way, the capability for science of candidate will appear behind his/her presentation skills and/or writing skills. But these skills are also very important for surviving, and may be a part of his/her capability… There is no conclusion for this story.