Some Common Job Interview Mistakes
You have worked hard to earn a Ph.D., and now you are looking for a job, either in an academic position (in a university), or in an industrial research lab, or perhaps in some other place where you have to use your recently earned qualifications. For this transition you have to go through a job interview. This is one of the most important “exams” in your life, since depending on its outcome your future may change in completely unexpected ways.
Having seen the job interview process from both sides, once when I was looking for jobs, and many times while interviewing candidates, I want to point out a few mistakes that I see many candidates making during their interviews. None of these mistakes is “fatal”, and stengths in other areas of the interview can overcome any of them. But why not avoid them if you can?
- Argue about assumptions instead of substance. Most job interviews contain a presentation given by the candidate. This presentation gives the candidate to focus on an important project which is representative of his or her past research. In many locations this presentation is interactive: the members of the audience can interrupt and ask questions during the presentation.
A good presentation starts with an introduction, which explains the setting of the research, and (some of) the assumptions under which the problem is solved.
(Here are some examples: we assume that “the cost of communication is much larger than the cost of computation”, or “we assume that we have a universal public key infrastructure“, or “we assume that we can completely replace the internet protocol IP with the protocol we have designed”, or “we assume that we can recompile all software with our compiler”.)
Many talks leave some of the assumptions unstated, and listeners have to be deduce them during the talk. I have seen two things happen quite often:
- The speaker and the listeners have different assumptions sets in mind during the presentation, and thus they do not understand each other, and they argue constantly about the quality of the solution.
- Even if the speaker and the listeners do agree on a set of assumptions, the listeners may not find the assumptions reasonable. For example, many listeners may object to most assumptions presented above. This can turn out into a religious debate.
Both these situations are highly counterproductive to the presentation.
If you are giving a talk and you sense that the debate steers towards assumptions, it is time to stop it immediately and re-focus it. The research has been done, and there is nothing you can do to change the assumptions you have used. You should not spend too much time to defend them either, religious wars are endless, and as a job candidate you have much more to loose than the interviewers by wasting precious time during the talk.
What you can say is the following: “These are the assumptions behind this piece of work, let’s make all of them clear. You may like them or not, but we cannot argue about them anymore. In this talk, I will show you what I have built on top of these assumptions. What you should judge me for is this construction — my research — and not the assumptions. The value is in the work, not in the premises. If you like the construction, perhaps I can do more constructions in the future, after you hire me, starting from a set of assumptions which is less controversial.”
- Attempt to hide obvious weaknesses. Sometimes during a presentation an audience member discovers some weakness in the presented work. For example, a very old benchmark was used for measurements, which does not stress enough current machine capabilities. Or there is some related research that the candidate did not know about. Or a theorem was used, for which the assumptions were not all satisfied.
One of the worst attitudes to take in this case is to defend your work, and to attempt to hide the mistake. “No, this benchmark is actually very good, because the machines in our lab are old.” “No, I didn’t read that work, but I know that that group does not use a sophisticated compiler like mine.” “I am sure that the theorem can be proved anyway.”
You have to realize that often during your interview in the audience there may be experts in the field of your research. Attempting to trick them with subterfuges will backfire badly.
The best thing, when discovering a mistake, is to first understand it (this shows that you can think), and second acknowledge it, and then to present the rest of the work, and show how it stands on its own. Hopefully, this mistake will only have a local impact, and it is not the basis for everything you have done in the last 5 years.
- Not care about the place where you are going. If you interview some place, you better care about that place: the people who work there and who might become your colleagues, the work atmosphere, the reward system, if you plan to do research how you get money for your research, and, very important, the health and wealth of the mother organization which is hiring you. If you interview some place and you never display an interest in any of these things, it shows you are not really committed to go there.
These are good subjects to discuss for some of the one-on-one meetings that usually occur during the job interview.
- Show modesty. Some people don’t like to boast about their achievement. The interview is the worst place to hide your qualities.
Some people prefer for their abilities to “speak for themselves”. Well, I have news for you: it doesn’t really work. People are too busy to guess your abilities, you have to use your mouth.
In general, do not assume people will think and infer something about you. “They will see I published papers in conferences both in theory and systems, so they will realize that I am an interdisciplinary guy.” If you think that interdisciplinarity is one of your strengths, put it in writing in your statement of purpose, or cover letter, or even better, on a slide in the talk (or all of them).
I am not saying you have to go around saying how good you are, that does not work, but one thing you have to be very careful during the interview process is about using negative labels for yourself. Even when joking. This is a long post already, so I will write some more about this topic another time.