As a converse to this question, as a professor, I find it difficult to conduct a useful interview. What types of questions should I ask which would give me a good idea as to how (1) productive and (2) self-sustaining of a student the interviewee may be? If different questions are required for each parameter, please mention that in your answer.
I underwent an interview recently from a prospective adviser, and I found the questions he asked of me to be pretty insightful - hence I'm sharing them here.
Why do you want to pursue research in this specific area?
This would highlight the candidate's motivation in wanting to do research in a particular field - and would also tell the professor more about the candidate's exposure to this area.
What made you apply to this lab/university, as a continuation of the previous question?
The answer would tell you whether the applicant had simply browsed the rankings list of universities, or did he/she actually go through the research publications of the lab - and the application was done due to an intersection of the two!
What would you like to be doing post Ph.D.?
There is no "right" answer to this, but it also tells a lot about the candidate's motivation in pursuing a PhD.
Finally, you can ask the candidate to discuss any problem that he is familiar with in that field - doesn't have to be anything fancy/complicated, but that would serve to highlight the clarity of the applicant's reasoning, communication skills, and level of exposure to the field.
In addition to the questions that shan23 has mentioned, I ask candidates for my group a few other questions:
What kind of advising style do they like? How "hands-on" or "hands-off" do they want me to be? If they want someone whose style is vastly different from mine, that's going to be a problem.
What is your preferred working environment? (When?, Where?, etc.) I just want to get a sense of what they're going to be like to work with.
What kinds of projects do they like? Do they want a methodology-driven project, or are they more interested in applications.
Have you spoken with members of my group? I want future group members to have an interest in who they'll be working with.
Ask them about their expectations out of their coming 3-5 years as a grad student!
I find that a significant portion of the frustration that I (and those others around me) have experienced is due to severe disparity between expectations and reality. Note that this is as much for the benefit of the prospective student as it is for you as the PI.
Specifically things to consider regarding expectations:
- The amount and style of supervision the student expects. My expectation was that I would "do science" and not "paperwork", in reality my PI knew less about the paperwork then I did, so I typically ended up needing to do a bunch of paperwork regarding employment (like salary raises, progress reports etc) and always late too...
- The abundance and lack of relevant competencies in the lab, for that proposed project. I was confident that the lack of computational competency at our lab wasn't gonna be a problem for me. I couldn't be more wrong..
- The workplace interaction with colleagues. I was under the impression that we'd be a team of intellectuals, tackling problems together, from our own angles. Again I was dead-wrong... Here, everyone's buried under their own pile of... Similarly, I can imagine that if the student expects to be a lone-wolf, forced team-work might be frustrating in the long run.
- How to handle getting stuck/frustrated. This is quite self-explanatory I guess..