There are a lot of examinations while earning a PhD. Many line up with major milestones of the degree. In general, these are: comprehensive exams, preliminary exams, and a thesis defense.
Of those, the defense was the most emotionally and mentally challenging.
The reasons why are summarized nicely in a blog post by Albert Kuo. Giving a public presentation, not wanting to disappoint anyone (especially your dissertation chair), and the unknowns of the closed-door session are all extremely anxiety-inducing.
In this week’s post, I’m revisiting that harrowing time in the hopes that it will help others going into this process for the first time.

My Dissertation Defense
My defense was, in total, about three hours long. I can break down the defense into three major parts: the public talk; the formal, ‘closed-door’ defense; and the results.
I began with a public talk. The talk was about 40-45 minutes and was followed by a few questions from the audience. As Eva Lansoght has observed, there exists a wide range of formats for thesis defenses across the world. I haven’t dug very deep into her work, but there also seems to be a range of formats for defenses at US institutions in this field.
In my department, public defenses are very rare. Up until recent years, PhD candidates simply defended in relative secrecy and then they were gone. Occasionally there might be a celebratory drink or a round of congratulatory messages in the student email chain. In lieu of the public talk, I think it’s more usual for the defense to begin with something along the lines of “Tell us about what you did and why.”
Following my talk, everyone, including me, was asked to leave the room so that my committee could get organized and prepare for the formal “closed-door” defense.
I returned to the room after a few minutes (probably no more than 5) for the formal defense. This lasted between 50-60 minutes. Following the defense, I was asked to leave again so that my committee could do their final deliberation. Most candidates pass their defenses, so this was likely more to discuss and write up what the focus of final revisions should be.
Finally, I was invited back into the room and was met by warm congratulations from my committee.
Preparing for the defense
A common theme that I’ve seen when looking at other defense experiences across the internet is the emotional toll that the thesis defense has on candidates.
I know this feeling well and can pinpoint two parts of preparing for the defense that affected me the most: the presentation and the defense questions.
The Presentation
The final two months leading up to my defense were a roller coaster of emotions. I submitted the final draft of my dissertation one month out from the defense, per the requests of my committee members. In the two weeks following, I didn’t think very much about my dissertation. It was out of my hands at that point.
But then the panic began to set in again as the defense drew nearer. Unlike many of my colleagues, I had opted to give a 40-minute talk on my work. There was, as a result, no precedent for this. The stress mounted.
Where the heck was I supposed to begin?
In the end, I relied heavily on these guidelines for thesis defenses. The structure of my presentation reflects several – but not all – of the sections highlighted on that webpage.
My own defense presentation was divided into four sections: introduction and background; methodology; findings; and conclusions. I also included acknowledgements and a selected bibliography at the very end.
The Questions
My feelings toward the formal defense followed a similar trajectory.
On the one hand, I was assured that this would be a great opportunity to discuss my work with people who had read it in detail. It would be more of an intellectual discussion than an interrogation (and it was!).
On the other hand, I had no idea what kinds of questions to expect.
My strategy ultimately ended up being this. I went back to past drafts of my dissertation. From those, I pulled questions, concerns, and suggestions from my committee’s feedback that I had not been able to address fully in the final version of my work. I sat down for many hours in that final weekend thinking through responses to those questions and concerns, should they come up again in my defense.
For the most part, those things did not come up.
In general, there are usually two kinds of questions that are asked during a thesis defense.
First, questions that concern “topic knowledge.” These questions ask “why” and “how,” and are generally founded on the understanding that you are the expert. From my own defense, this included, among other things, a question about how my work was affected by COVID.
Second, there are other questions that are meant to encourage critical thinking and application. Most importantly, they require you to consider the broader implications of your work. Why should what you have done matter to others in the field?

Major takeaways
There are three pieces of advice that I would give to anyone who’s on a path to the PhD defense.
First, do your research. Most of what I learned about the defense structure came from my advisor and my peers. I cannot recommend seeking out advice from recent grads in your program enough. Although I knew what to expect in general, there’s virtually no way to completely prepare for the ‘closed-door’, question portion of a defense. But there are many resources, including lists of potential questions, that you can find on the internet that might be useful.
Second, know what happens before and after the defense, as well as during it. This is absolutely key for a lot of reasons, but I’ll just highlight two here.
- Much of the defense-related paperwork must be completed by various members of your committee. However, it’s ultimately up to you to make sure they do it and on time. Follow up with your committee throughout the process, and often.
- Scheduling your defense has a direct impact on how much time you have between then and final submission. In the early days of deciding on my defense date, I believed I’d need months to complete potential revisions. In the end, a little over one month was all I had and that was enough. When it comes to revisions, they can be “minor” or “major.” In most cases, your chair would not have let you defend your dissertation if they believed that you’d need to make major changes afterward.
Third, if possible, get yourself a defense note-taker. This is pretty common practice in my department, and generally recommended for three reasons.
First, it’s a great way to experience first-hand what happens in that “closed-door” formal defense. Although each defense is unique, it can be helpful to get a sense of what kinds of questions certain professors ask – especially if one of them is also on your own committee!
Second, I don’t know about you, but I frequently blackout when I am under extreme stress. I am certainly paying attention in the moment and can formulate relatively coherent responses to questions.
But I cannot both participate in a discussion and take notes at the same time.
Having someone else there to take notes for you throughout the defense gives you one less thing to worry about. It’s also a helpful record of what was discussed, especially if there were specific recommendations that you want to follow up on later.
A final benefit of having a friend take notes for you is that it’s just a comfort to have someone else in the room with you that you know is 100% on your side. (Not that any of my committee members were antagonistic or asked anything in bad faith.)
Thesis defenses are scary for a whole lot of reasons! I think it’s nice to have a peer go through it with you, even if they aren’t an active participant in the discussion.
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