Interview questions

So when a graduate student wants to join my lab I ask them a few questions to see what kind of person they are (one toxic person can destroy a group) and also how fundamentally sound they are in their science. For undergrads I just look at GPA. Some people have told me this is unfair, but I think it’s plenty fair. I thought it’d be interesting to post the types of questions (not the exact ones):

Explain what these symbols mean: J=-D∇φ, bonus for knowing what the equation is

Solve this for y: dy/dx=x

Imagine a hole in a cup with a telescoping rod. When we fill the cup with water, how do we ensure the rod can still telescope without leaking water.

Which melts faster given identical volumes of starting water: a frozen bucket of the water, or snow made from it?

If I have an overheating component, how do I fix it?

Which will produce a stiffer gold rod: an electroplated or drawn?

Drawn a stress diagram for a beam in bending

Explain how [insert-organ-here] works

If I have a hollow sphere with reinforcing fibers embedded in the wall, what directions should the fibers be oriented for strength

For this, I pick and choose based upon what I want the student to work on as their project. For instance, if they’re heavy on the computational side I’ll throw in some more math and maybe some more materials questions. Also, for some of the questions I really don’t care if they’re right. I focus more on how they think through a problem. A colleague said this was a way to scare the students off, but my thought is that I don’t care. These are adults that in probably a year will have to stand in front of a room of very smart people and give a focus research talk, after which, they will get grilled by a bunch of strangers. If they can’t handle a one-on-one and don’t know these simple topics that they will have to apply then I really don’t want them in my lab. For the undergrads there’s room for growth, for the grad students I want them to deliver.