Hardest (or weirdest) question you were asked during your candidacy exam?

One of my Ph.D. students will be taking his candidacy exam soon. This is the exam, also known as “qualifiers” or “orals” at some universities, that tests whether you have the background knowledge to get a Ph.D.

In order for candidacy exams to fulfill their purpose, profs have to ask hard questions. An excellent way to figure out how much a student knows (and to see how they think through problems to which they don’t immediately know the answer) is to keep pursuing a line of questioning until you exhaust the student’s knowledge. Of course, that’s not the only reason profs ask hard questions. One unofficial purpose of candidacy exams everywhere is to let profs prove to students that they know more than the students do. Plus, it’s a traditional ritual profs had to go through themselves, and so they’re darn well going to make their students go through the same ritual. πŸ˜‰

My own candidacy exam actually went quite well. Maybe my profs were feeling kindly that day*, but they never really pushed me to the point where I just had no idea how to answer. The question I remember best is one Peter Morin asks all his students: Name five famous female ecologists or evolutionary biologists and summarize their contributions to the field.

I know of an amphibian community ecologist from Duke whose exam began with one of her committee members sliding the latest issue of an evolutionary journal (which had just arrived in the mail that morning) across the table at her. The cover featured drawings of several fossil fish. The committee member asked, “So, what do those fossils illustrate about fish evolution?”

At Rutgers, one of my friends was once asked, “You’re reading a French biology journal and you come across the acronym ADN. What does it stand for?” Note that Rutgers is an English-language university, and neither the student nor the prof knew French. (answer below)

I don’t have any anecdotes relating to any questions I myself have asked. For better or worse (and I think it’s a bit of both), candidacy exams in my department are somewhat narrowly focused and there are rules to prevent profs from asking overly wide-ranging or off-the-wall questions. So I don’t know that any of my students will ever get to have any really good anecdotes about the ridiculous questions they were asked during their candidacy exams.

So what’s the hardest (or weirdest, or most memorable, or whatever) question you were asked during your candidacy exam?


Answer: ADN stands for DNA. Apparently the prof had just learned that the French acronym for deoxyribonucleic acid was ‘ADN’, and found this bit of trivia so interesting that he decided to ask the student about it.

*Or maybe I had left enough books on my desk that morning. The rumor in the Morin lab was that Peter would come in to your office very early on the morning of your exam, look at all the books on your desk (which you had presumably been reading in order to prepare for the exam), and not ask you any question that you could answer by reading any of those books. I don’t actually know if Peter does this. But it does raise the possibility that, if you had enough books on your desk, you could prevent Peter from asking any questions at all. πŸ˜‰

27 thoughts on “Hardest (or weirdest) question you were asked during your candidacy exam?

  1. My hardest question came at my defense, not my qualifying exam. My advisor, Roger Nisbet, said something like, “Suppose you had a metapopulation spread out over an intermediate number of patches — dozens of patches, say. How would you approach this theoretically?” Another committee member who didn’t much care for me laughed and said “In physics, we call this the realm of no theory.” Later, Roger explained, “I wanted to see how well you thought on your feet, so I threw you something hard/impossible.”

    • Presumably you answered: I’d look at the limiting cases of small and large numbers of patches to get a sense of how the intermediate case might behave, and then follow up with a bunch of brute-force simulations of the intermediate case?

      • They were looking for more than that. As I recall, I suggested looking at the clustering of the patches, suggesting that some sort of coarse-graining/real-space renormalization might be possible if you were lucky.

  2. I was asked to explain why microcosm experiments are utterly and completely worthless in all respects, now and forever, but that was piece of cake of course. πŸ™‚

    I had a very easy committee; I think they felt sorry for me. I think somebody asked me about the effects of abscissic acid, or maybe ethylene or auxin, on plant development, which I guess I knew then but I sure don’t now. (I was in the Plant Biology, not Ecology, department). Another guy asked me something about organellar genome structures I think, but I had some background in mobio so was ready.

    The only thing I really remember is that I was shooting jump shots 10 minutes before the exam to try to calm down, which helped a lot actually because I was a basket case.

    • I assume your answer to the microcosm question was “trees are basically just big algae, so microcosms are a great way to study forest dynamics”. πŸ˜‰

      • I just took that one step further and argued that hey, if you know something about something, then really you pretty much know everything about everything, and all further questions are therefore pretty much pointless.

      • Now that would be a gutsy answer!

        Probably the only way to get away with that kind of answer would be to have no reason to care if you fail the exam. Apparently F. Scott Fitzgerald (? may be misremembering who it was, but it was someone who went on to become a famous writer) once was taking a final exam for a large undergraduate course at Princeton. A few minutes into the exam, he walked up to the front of the room, tore up his exam in front of the professor’s face, and walked out.

        Which he could do because he wasn’t actually taking the class. πŸ˜‰

      • Well, I’m sure there were a combination of factors, including the length of the exam. His interest is computation and evolution, as well as evolutionary theory. I had rotated in his lab. He also had a creative side and liked to explore ideas. If I had been less fatigued, I might have tackled the question. As it was, it finished the oral exam.

  3. To start off my exam Peter Chesson asked me to relate the various types of seed germination strategies to Shakespeare’s quote “Some men were born great, some achieve greatness, and some have greatness thrust upon them”. It set an interesting tone for the rest of the exam.

  4. I was asked to draw the molecular structure of the four nucleotides. I was then run through a battery of questions about the emergence of different floral and faunal groups in the geologic record. If I paused from drawing to try and answer the questions I was asked to please continue drawing before they would continue. It was good-natured but got me very flustered.

  5. Our preliminary exams revolve around proposed research instead of breadth of knowledge in the field. The question I most remember was toward the end of my exam (when I was quite tired). I was asked by one of my co-advisors, “so what if you do everything you proposed and try all the various approaches you’ve considered, and in the end none of it works out. Then what do you do?”

    • I actually much prefer the practice of separating the candidacy exam and the evaluation of the research proposal. They are, or should be, two very different things.

      It’s the committee’s job to make sure the student has thought about the ‘worst case scenario’. But usually the question would be couched a bit differently, since if you think of the worst case scenario as “everything you do, or could do, fails”, then by definition there’s nothing you can do about it.

  6. The worst question I got was “Are you sure?”. Which, of course, led me into a spiral of wrong answers as I re-labeled the axes for an Island Biogeography question (species and rate of immigration), only to end up where I started. There were harder conceptual questions, but that one caused me the most embarrassment. I got the initial response correct, but was so nervous that I couldn’t recognize the question for what it was: a test of confidence.

  7. While I can’t recall any specific or extraordinarily difficult questions, what scarred me the most was having to extend my orals into two sessions. On the day of my orals, one of my four committee members fell ill, I completed the session, and, to appease ‘The Rules’, I had a second session scheduled so the ill member had a chance to drill me. From my advisor’s response (and later discussions with the ill member), the decision to extend the oral examination wasn’t due to ambiguity in whether I should have passed or failed, but another member’s devotion to going by the book. Thus, instead of being relieved of the stress of oral exams as I traveled for field work the next two weeks, I was blessed with worries about doing it all over again…

    • That sucks. At Calgary, if a committee member falls ill on the day, the rules permit the neutral chair (a faculty member not on the committee, whose only job is to chair the meeting and ensure the rules are followed) to ask questions provided by the ill committee member, with the attending members of the committee evaluating the student’s answers. I actually was the neutral chair for such a candidacy exam, where the adviser was absent due to illness. It worked out fine.

      • We may have similar rules at my University, and I vaguely recall my committee members requesting questions from the ill member, who wasn’t concerned with orals given my performance in writtens. It’s surprising to me that advisors fall under that rule though, given that they have a larger stake in a student’s performance in the exam…

      • Advisers have plenty of opportunity to interact with and evaluate the student (they complete the annual progress reports, for instance), but the candidacy exam is one of the few times when the rest of the committee gets to evaluate the student. Nor are advisers unique in their ability to probe or evaluate the student’s background knowledge. So for candidacy exams, the adviser’s attendance isn’t any more crucial than attendance by any other committee member, and might even be less crucial.

  8. Just when I was warming to the idea of pursuing a phd (I’m finishing my M.S. at the moment) this post comes along and reminds me how needlessly stubborn and stressful academia can be.

  9. My orals were actually not too bad, but the most memorable part was that Bruce McCune brought in an unmarked box that he kept closed until his turn came at the end of the first round of questions. It turned out he had brought in plant and bryophyte specimens he collected that morning for me to identify and spur discussion of natural history. Since my exams were in February, the plants were mostly rosettes of common weeds so I think I got off pretty easy. But I think the rest of my committee was impressed that I remembered which part of the moss is the sporophyte and which the gametophyte, and their ploidy, which I had thankfully reviewed a couple years before when teaching Introductory Biology labs.

  10. All I can say is thanks guys, I am taking my comps in Policy/Medicine/Interdisciplinary studies in two days, and reading these posts made me feel much better. Will let you know how it goes!

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