Preparing for a PhD Interview in Physics

The other day I was chatting to a group of our 4th-year MPhys students about the process for applying  (and hopefully being interviewed) for a PhD. This is the time when students in the UK have started to apply and are awaiting decisions on whether they have to go for an interview. Final decisions are usually made by the end of March so those with interviews have a busy couple of months coming up.

I actually quite enjoy doing PhD interviews, because that involves giving excellent young scientists their first step on the ladder towards a research career. I’m sure it’s not so pleasant for the candidates though. Nerves sometimes get the better of the students in these interviews, but experienced interviewers can calibrate for that. And if you’re nervous, it means that you care…

Anyone reading this who is nervous about doing a PhD interview (or has experienced nerves in one they’ve already had) might reflect on my experience when I was called to interview for a PhD place in Astronomy at the University of Manchester way back in 1985. I was very nervous before that, and arrived very early for my grilling. I was told to wait in a sort of ante-room as the previous interview had only just started. I started to read a textbook I had brought with me. About five minutes later, the door of the interview room opened and the interviewers, Franz Kahn and John Dyson, both of whom are sadly no longer with us, carried out the unconscious body of the previous candidate. It turned out that, after a couple of friendly preliminary questions, the two Professors had handed the candidate a piece of chalk and told him to go to the blackboard  to work something out, at which point said candidate had fainted. When it was my turn to be handed the chalk I toyed with the idea of staging a mock swoon, but resisted the temptation.

The question, in case you’re interested, was to estimate the angle through which light  is deflected by the Sun’s gravity. I hadn’t done any general relativity in my undergraduate degree, so just did it by dimensional analysis which is easy because an angle is dimensionless. That gets you within a factor of a two of the correct answer which, in those days, was pretty goood going for cosmology. That seemed to go down well and they offered me a place … which I turned down in favour of Sussex.

In those days, before detailed information about research in University departments was available online, the interview generally consisted of a discussion of the various projects available and a few odd questions about Physics (and possible Astronomy) to see if the candidate was able to think on their feet (i.e. without fainting).

Nowadays it’s a bit different. You can still expect a bit of questioning about undergraduate material but that is normally preceded by the chance to talk about your final-year project. One reason for that is that selectors are interested in project work because it can provide evidence of an aptitude for research. The other is simply that it gives the candidate a chance to get over any initial nerves by talking about something that they hopefully know well, as they will have been working on it for some time.

My first piece advice for students who have been offered an interview, therefore, is to prepare a short (~10 minute) verbal summary of your project work so you’re not wrong-footed if asked to talk about it.

Students nowadays are also expected to know a bit more about the thesis topic in advance, so my second tip is to  read up a bit of background so you can talk reasonably intelligently about the proposed research. If, for example, you have decided to work on Dark Energy (as many seem to these days), you won’t come across very well if you don’t know what the main issues are. What’s the observational evidence? What kind of theories are there? What are the open questions? Same goes for other fields. It also will do no harm if you read a couple of recent papers by your prospective supervisor, for reasons of flattery if nothing else.

Anyway, I think those are the two main things. If anyone has other advice to offer prospective PhD students, please feel free to add via the comments box.




8 Responses to “Preparing for a PhD Interview in Physics”

  1. We always schedule time for the candidate to ask questions. First, always ask a question. Second, never ask a question that’s answered on the webpages, especially in the FAQ section…

  2. I would ask them why they want to do doctoral work in the first place. If the answer is “academic career”, then one should give an honest opinion about the chances.

    • Bryn Jones Says:

      When students asked me for advice about what to say in interviews for PhD studentships, I always told them to reply to any question about their reason for applying by saying they were interested in the subject, not that they saw it as the start to an academic career. That would show that they understood properly the nature of the academic career system, where only 5%-10% of people embarking on PhD study in astronomy (and many other sciences) can hope for an academic career.

      Then one student countered that she had heard one academic regarded a commitment to an academic career as indicating that a student was dedicated to the work. So the trouble here is that some academics have as unreasonable a set of expectations as some students do.

      • Of course, the interests of the student and the supervisor are not always the same. It might very well be that the supervisor’s interests are best served by someone who thinks that he has a chance at an academic career (whether or not that is the case). This can also be in the best interests of the student (whether or not he has a chance at an academic career), at least in the short term, but not necessarily.

      • Bryn Jones Says:

        Yes, I agree.

  3. Chris Chaloner Says:

    As well as the obvious academic questions and statements, I would recommend asking about pastoral care by the Department. The PhD years are probably the loneliest in a career (whether academic or industrial) because the student will be working alone much of the time, rather than in a team. I know from experience of relatives that some Departments effectively take no interest if the student develops depression, for example – not even informing parents (claiming that they cannot interfere in medical issues of adults). Interrogate the Department about completion rates and completion times!

    • “the student will be working alone much of the time, rather than in a team”

      It depends. For some, the doctoral years will be the first they have worked in a team, rather than alone.

  4. My advice would be not to run up seven flights of stairs just before your interview. I was a secretary at the department and the poor lad, mentioned above, appeared at my desk red faced and puffing and was immediately rushed into the interview. Even if you are late, take the lift.

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