Over the last few months, I’ve been fully immersed with the CS PhD application process. I’ll make a later blog post detailing the overall process, but I thought I’d write up a quick post about my recent experiences (and hopefully future!) with the interview portion of the process.

Process Overview

The interview is just another step in the overall process of the PhD application cycle (see this post for an overview). Whether or not schools do interviews and when they send out interviews varies heavily between schools, departments, and even faculty. I’ve heard of many EE departments sending out requests much earlier than CS departments, and personally have received requests at varying times of the month (from early January to other days). Some schools don’t send out interviews at all, which I have been told is quite normal too. There is a great variation between applications, so I wouldn’t be worried if you haven’t or don’t get interviews! I definitely was regardless.

If you do get an interview however, this is a great sign! It generally means that you’ve been selected to a shortlist of candidates that faculty are interested in learning more about. For example, for LTI at CMU, Yonatan Bisk has a fantastic overview of the rounds that admissions committees go through, and interviews are among the latest rounds of the process (right before decisions). I want to go over what the interview is about and should be like (from what I’ve gathered online), and then also give some perspective from my interview experiences.

What the Interview is About

As I said about, the interview is generally a chance for faculty to get to know you better. Most of the time it is not a technical interview in the way of testing your knowledge (but can be, as I mention below), and rather checking if you are who you claim to be in your SoP.

The first main part is a background check. Expect questions about the work you mentioned in your SoP like research projects. You should be able to explain your research starting from a surface level pitch to in-depth technical explanations, and be able to defend the claims you made or the reasons you investigated your hypotheses in the first place. If I’m an interviewer, I want to see that you understand the research you were doing, and also see how much of it you actually did (it’s fine if you didn’t do everything! as long as you’re clear about it). This also gives a good sense of how research-ready you would be in a PhD. Some people suggested making slides, but I haven’t been told to by faculty yet, so I erred on the side of having them but not needing to use them.

“Your interviewer should not know more about your application (excluding recommendations and other confidential info) than you do! That would certainly not look good.”

You’ll also probably get general background questions, from “Tell me about yourself” to “Why are you pursuing a PhD?”. These help paint a fuller picture of who you are and what your goals are for pursuing the PhD. It is a 5-6 year commitment after all, so I sure hope you know why you want to! Alvin has a great post for deciding if a PhD is even right for you here.

The second main part is understanding research alignment. You want to be able to demonstrate that you understand what research ideas you’re interested in pursuing during your PhD, and that there’s some overlap of interest with your potential PIs/advisor. This is ok to be less fully fleshed out, but demonstrating that you understand how to synthesize possible directions is a critical part to get right. Some advice online has been to look at previous papers of your potential advisors, but this hasn’t been useful for me personally.

It’s fine if your topic is broad or if you’re still settling on something specific from what I have understood. After all, most PhDs or even professors don’t even know what specifically they want to work in the next 5-6 years (or they don’t stick to what they say). Your interviewers should understand this point, so I wouldn’t stress too much about the exact topic. Being able to talk about it with some concrete evidence/relevant papers is most important.

The last part generally is your chance to ask questions to your interviewer. This is just as important to demonstrate interest for the school, as well as to gain a better understanding of the lab and the group as a whole. Ask questions about how the lab is structured, what projects are of current interest, freedom, expectations, advising style, etc. Hopefully there are things you want to know before committing to schools, so this is a good chance to learn. However if you are later admitted, you will still get a chance to talk to current grad students who may better to ask, so don’t go overboard here!

Some concrete tips I’ve gotten that helped me and may help you:

  • Understand what your 5 second, 30 second, and 2 minute explanations of projects are. You should always be prepared to explain your research at these three levels of detail, in a one sentence overview or a paragraph detailed explanation. This helps immensely with giving a high level overview before diving into technical details.
  • Know your SoP inside out. Someone else remarked that your interviewer should not know more about your application (excluding recommendations and other confidential info) than you do! That would certainly not look good.
  • Practice talking about what you want to work on to people to flesh out your ideas better. It was hard for me to give feedback to myself on my ideas, so presenting to research mentors and friends helped a lot.

My Interview Experiences

For myself, I received a few interviews from different schools, and multiple from the same school! Some of them I received pretty early on in January, others towards the end. Even at the same school there were large variations in the kinds of interviews I had.

Overall, I would say the standard interview experience is 30-45 minutes following the structure above. I was able to pick which of my projects I wanted to discuss in detail, and often spent a good chunk of the time discuss some of the technical aspects as well as the surprises or setbacks I came across in my projects. I’m glad I chose projects where I had a heavy hand in the research which helped me communicate my understanding and role. I was surprised by some other left field questions about my background, but they were pleasant and helped me talk more about other aspects of myself that weren’t directly related to research but still were a big part of my identity and future focus. I also had a technical question in one of my interviews which was surprising, but nothing that required extra prep or that was too difficult.

Discussing my research interests went less well as I had a shaky description of the topics I was interested in, but throughout my interviews I was able to refine it further. It’s why I recommend discussing it with friends as a lot of ideas make sense in our heads but become difficult to express to others! However, I still had a great time in my interviews and had fun talking about research.

I’m writing this post kind of early, so I have yet to see what the feedback from schools is, but when I do I’ll update this post or make a followup post later. If you’re going through interviews soon, congratulations and best of luck! It’s overall a fun experience to talk about research in depth with potential faculty advisors, so try your best to enjoy it.