Photo: A “nailed” thesis abstract (photo S. Heard)
I recently returned from a trip to Stockholm, where I went to be the “opponent” (in North America, we would say “external examiner”) for a PhD defence. Get this: at the defence, the PhD candidate didn’t present his work – I did. Curious? Read on.
It’s no surprise that academic systems vary – but the “opponent” system used in a number of European countries is an interesting variant, and one not well known (I think) in North America. My sample size is very small, of course, involving one defence at one university in one country*, but I was impressed. I’ll describe my experience, and share some thoughts about its advantages and disadvantages compared to the North American convention.
I was invited to be the opponent about five months before the defence. About two months before the defence, I received the candidate’s thesis. That seems like a long time, but I needed to work harder on this than on a typical North American defence, so I was grateful for the time. You’ll see why as I go on.
Although I didn’t participate in this part, about three weeks before the defence, the candidate had a “nailing” ceremony – in which the Abstract of the thesis was (literally) nailed to a plank in a department common room. The nailing symbolizes the public release of the thesis, which cannot be defended until it has been public for three weeks. (The whole thesis, of course, is made available electronically at the time of the nailing.)
At defence time, I flew to Sweden to spend two days in the host department. The day before the defence, I gave a seminar in the host department (as one does). More importantly, the candidate and I went for lunch, along with his supervisors and the Chair of the defence. This lunch serves to let the candidate meet the opponent in an informal, low-pressure setting, rather than at or just before the defence. (The Chair of the defence was there, though, to enforce a rule that we not talk about the thesis.) This contrasts with the North American system, in which the external examiner is discouraged, or even disallowed, from making any contact with candidate or supervisor before the defence.
The day of the defence was a big day and a long one. The defence, in the morning, was attended by ~80 people, including students and faculty but also a large contingent of the candidate’s friends and family. Here’s how it went:
- The candidate was up first, with 10 min to speak – but only to introduce the study system and the most important methods he had used.
- Next, I presented the candidate’s thesis, taking about 30 min to introduce the context, present the methods, results, and interpretation, and to discuss its meaning for the broader field. I used a powerpoint illustrated with graphs and other elements taken from the thesis, but also material I gathered myself. This, of course, is exactly what the candidate would do him/herself in a North American defence. But here I was doing it instead – with the candidate, who knew the work far better than I did, sitting right in front of me. His presence, by the way, made it obvious that I couldn’t count on my usual reason for not being nervous when I give talks.
- Following the presentations, the candidate and I sat at facing tables at the front of the auditorium, and I questioned him for about an hour. This was just like the North American questioning by the examining committee, except that it was one-on-one: the 3-member examining committee just watched and listened.
- When I had finished, the examining committee had a chance to ask some very brief questions, and then the audience had their turn. These together took less than 10 min, though, and obviously weren’t a critical part of the candidate’s assessment.
- The Chair then declared the defence closed, and the candidate and audience left. The examining committee asked me for my overall assessment and comments, then the asked the principal supervisor the same.
The supervisor and I then left, so the examining committee could deliberate. (We left the room to discover a very large party in progress, with snacks and multiple bottles of champagne. Pass or fail, the bubby had already been poured!**) You’ll notice another big difference from the North American model here: I wasn’t a voting member of the examining committee. My role as the opponent was to give the thesis, and the candidate’s knowledge, a good airing out; but I did so to help the examining committee judge the defence, not to judge it myself.
- After perhaps 5 minutes, the examining committee emerged to announce the candidate’s success.
That was the defence, but it wasn’t the end of the day. There was another lunch for candidate, opponent, and committee; and then in the evening, a very big party including dinner, toasts and toastmasters, speeches, songs, gifts from supervisor to candidate and candidate to supervisor, and dancing that lasted longer into the wee hours than I did. Of course we celebrate defences in North America too, but I was struck by the scale of the celebration and the involvement of family and academics on an equal footing.
Advantages of the “opponent” system
The biggest advantage of the opponent system is that it ensures independent review of the thesis by someone who knows the thesis very, very well. I had to know the thesis inside out and backwards, because I had to present it! And my knowledge (or lack thereof) was on conspicuous display, so the examining committee could be sure of it. (I rush to assure you that when I’m an external examiner in the North American system, I take the job seriously; but I won’t try to argue that I absorb every thesis in the detail I absorbed this Swedish one. And, of course, not every external examiner is as conscientious as I claim to be.)
Another strength is that the opponent’s presentation of the work (rather than the student’s) gives the examining committee two different perspectives on the interpretation and importance of the research. There were several points where I think I interpreted the results and what they meant for the big picture a bit differently than the candidate did. This makes the defence more interesting, and it also aids the committee’s assessment of the way the work challenges or changes our understanding of the thesis topic.
Finally, the opponent system disentangles two different function of the examination: on the one hand, discovering (if you prefer, putting on display) the work and the candidate’s understanding of it; and on the other hand, judging that work and understanding. This means, for instance, that the opponent can disagree fervently with the thesis, but the examining committee can judge the candidate’s response without having a direct stake in the disagreement.
Disadvantages of the “opponent” system
The main disadvantage of the opponent system seems to be its placement of a lot of eggs in one basket. I presented the thesis and examined the candidate almost single-handedly. What if I had done a poor job? What if (despite my close-reading-assurance argument above) I hadn’t read the thesis carefully? Or had misunderstood it, or missed a major issue? Or simply stopped questioning the candidate after a few minutes? I’m told in cases like this, the examining committee is expected to step up; but for the very reason that the opponent will (usually) be overprepared, I wouldn’t be surprised if the other examiners were sometimes underprepared. Such defences must happen, but I don’t know how often.
I suppose one could argue that another “disadvantage” of the system is that it’s a lot of work for the opponent. I don’t know if this makes it more difficult to secure an opponent for a defence. I’d accept another invitation in a heartbeat, and if I’m typical, this isn’t really a concern.
Finally, I’m told that a disadvantage of the system’s naming (rather than of the system itself) is that North Americans sometimes interpret the English word “opponent” too literally. I wasn’t there to oppose the candidate’s work, but rather to hold it up to the light – by presenting it with both praise and criticism and by probing the candidate’s understanding. This certainly makes rigorous questioning appropriate, but not one-sided or unreasoned opposition. Fortunately, I was well briefed!
There’s more than one way to skin a cat, and I think more variance in the quality of PhD exams is explained by choice and behaviour of examiners than by opponent vs. external examiner system. So I don’t think either system is “better”. I do think that comparing these different systems is a useful way for us to think carefully about what it is we’re trying to do when we examine a PhD thesis. It’s funny that the thesis and its defence is considered a critical, even defining, piece of a student’s graduate education – but I’ve never had any formal instruction in, or heard any formal discussion of, what we’re doing when we examine one. My “opponent” experience made me think about this a bit; maybe hearing about it has done the same for you.
© Stephen Heard (email@example.com) June 16, 2016
*^Want to triple that sample size? Here’s Carol Boggs’s account of her experience. But both of us were at Stockholm University. Here’s a description from Jonas Waldenström of the defences of two of his students. But the process differs in details among universities and definitely among countries – in Norway, I believe, the candidate presents the thesis; in Finland, the opponent does but the process is enriched with top hats, robes, and a sword (really). I’m sure there are many other variations.
**^Just as in North America, failures at the defence stage are quite rare. This is not because the process isn’t rigorous. It’s because we don’t allow students to reach the defence stage until we’re confident that the work is excellent and the student can defend it well. This makes the defence usually more of a celebration than a bar-hurdling – but only because the bar has already been hurdled.