Dissertation Defense Presentation Tips

How to Prepare for the PhD Defense

The preparation for the PhD Defense was just one step in the long road to the defense, that started with the first draft, then dealt extensively with the committee members, and ended with the celebration of getting my degree (I got the diploma in my hands right after my defense).

Between returning from a conference in the USA, and my defense, I had less than a week of time to get over the jetlag and prepare for the defense itself.

In an earlier post, I summarized my approach for the defense as follows:

I didn't really know how to prepare for my defense, and I'll write a post about it specifically in the future, but essentially I didn't have much time for preparing my defense all in all. Certainly, I had to prepare my "lekenpraatje", and I reread my dissertation once more, but preparing for possible questions was a little more vague. I summarized my dissertation in a sentence per page, as suggested by Phillips and Pugh, I went over my meeting notes again, and I tried fishing for information from my committee members (unsuccessfully).

Let me break that down into more detail, so you have an idea of how I prepared for my defense (which, honestly, went really smoothly after I got a hold of my nerves):

1. The presentation

In Delft, we give a "lekenpraatje" for our friends, colleagues and family, but not for the committee members. Therefore, the presentation doesn't really matter towards the result of the viva itself, but it is nonetheless a very good opportunity to show an overview of your work to everyone you invited to attend your defense.
I made the slides about a month before the actual defense date, but then needed to reshuffle a number of times to be able to fit the talk within the 20 minutes of allotted time. While in Pittsburgh for IBC, I took off an afternoon to practice this presentation, and during the week before the defense I ran through my presentation a couple more times. I wanted to have it rehearsed very well so that I could almost run it on auto-pilot.

2. Rereading the dissertation

Before the conferences that I attended, I reread my dissertation a final time. It was already printed by then, and of course, I found a number more mistakes in my text. While rereading for a last time, I made a summary (see point 3), and paid extra attention to my theoretical chapter, as most criticism from the committee members had been geared towards my proposed model.

3. Making the summary

As suggested by Phillips and Pugh, I summarized my dissertation in one line per page as I was rereading it. Certainly, having the activity of writing something down, and thinking of how to summarize a page, was a good change from all the reading of the same text that I had done earlier.
However, I am not sure if it was really worth the effort. I never looked at that summary again after making it. I'm just assuming that spending time with my text in this manner triggered some extra area in my brain, or something like that, but it might have been too much effort.

4. Going over meeting notes


Based on my notes of the meetings that I had with the committee members, I tried to distill their main points of criticism, and turn that into a question. I also verified if I made all the changes they required, or if I had left loose ends on a few topics. For those topics, I made sure to be able to explain why I didn't pay more attention, or to give an outline of a possible solution.

5. Fishing for information


Sometimes, committee members are known to give you their questions in advance. In my case, only my copromotor and promotor gave me some ideas of what they could ask, but I had no clue of what the other members would be asking. By going over my meetings notes, I refreshed their "pet peeves", and in some cases that turned out to be a good direction. I also contacted my committee members to see if they wanted a final meeting to prepare for the defense, or if they wanted me "to bring some extra material to put on the projector during the defense" (this is how I tried to fish for information, but they all just told me that there was no need for a meeting or additional material).

6. Thinking of possible questions

As I was left with my meeting notes and some advice from my copromotor, promotor and colleagues, I sat down to make a list of possible questions. These questions, I started to work out on paper, in an orderly fashion, so that I could put them on the projector during the defense. One of these questions indeed popped up, and my friends thought the committee member had given me that question before the defense. It was good guesswork instead. I tried to list about 5 possible questions per committee member.
Moreover, I used the top 10 viva questions that I got through Twitter.

7. Working out some additional material

I found some more interesting papers a few days before my defense, so I made some notes and played around with some of these ideas. That material came with me to the defense, and I was planning to show it while answering the final question, but I was interrupted by the Beadle. My dissertation is not a completely finished piece of work, there are always additional questions that remain to be answered, and I focused on continuing a little bit on the loose ends to show the committee that I have given these leads some good thought.

8. Gathering relevant literature sources


I took the "really important" papers with me that I had used as a basis for my theoretical work - just in case I needed to put something on the projector during my defense.

9. Get enough sleep

Getting past the jetlag and getting the fog out of my brain were about my major concerns for the defense. Somehow I knew that if I had a sharp mind, I'd be doing well that day.

10. Look around online

An excuse to browse the interwebz once more? Maybe, but I certainly found great advice about the defense here and here (also check the list of references).

How did you prepare for your defense or viva? Did you spend a lot of time on it, or were you pressed for time like me?


Well, I’m back. After 3 months of intense thesis writing, revisions, and successfully defending (all while working a part-time job in industry), I want to share with you Part 1 of 3 of this series. Part 2 will be how to finish your thesis in a timely manner (and write a good quality thesis). Part 3 will be life after a PhD, making the transition into the workforce, and how to prepare ahead of time (i.e. apply for jobs before, during, or after writing your thesis).

First, what does it take to give a successful PhD Defense? How can you prepare, keep the stress levels low, and make sure you have the highest chance of success?

I’ll just say that everyone’s PhD Defense is unique and is unpredictable. Your talk/presentation is only as good as you want it to be. And you cannot fully prepare for all the endless possibility of questions. If you wrote a 200 page thesis, your thesis commitee can pick apart an error bar on a graph on page 133. They can ask you what you meant by a word in a random sentence in any given paragraph. Keep in mind, this is all just apart of the PhD hazing process, and in a sense is just to humble you. At the end of the day, if you wrote a good quality thesis and are CONFIDENT, you should have no problem successfully defending and leaving that room with a sense of relief. Either way, I wanted to share my experience while it is still fresh in my mind

1) Do not underestimate how long it takes to prepare your slides/talk and make sure you give multiple practice talks

When I turned in my thesis two weeks ahead of time to my committee, I thought the hard part was over. Although a very important milestone, don’t let your guard down. If you already have most your slides ready to go, then you are lucky. I ended up getting data at the last minute and my story changed. I had to make many model slides from scratch.

If you want to give a GOOD thesis talk, you need to practice multiple times. And this means that you don’t cram it all in a couple of days right before your talk. I’m not talking about giving just one practice talk. You need to give multiple group practice talks. In between, you need to practice on your own.

You certainly don’t have to memorize every word of your thesis defense talk, but you should have it well-polished. There is no limit (or requirement) on how many practice talks you should give, but give as many talks as it takes until you feel like you are ready. If you are unsure of the quality of your talk (or being “ready”), tape record yourself or watch a video of yourself to see just how good it is. You might be surprised when you play it back to yourself.

You should also time your talk. I noticed that I tend to talk faster (by about 5 minutes) when giving the actual public talk vs. when I practice on my own. The length of the talk can depend on many departmental factors. My talk was ~45-50 minutes long which also leaves time for questions.

Either way, do not procrastinate on your slides and/or talk until days before. Make sure you use the full two weeks to perfect your slides, polish your talk (and be very concise about your words), and review material you are unsure about.

2) Listen to other thesis defense talks

The best way to mentally prepare for your thesis defense talk is to listen to other thesis defense talks. I actually went and got a few talks on DVD (the good ones that I remembered). If their research is on a similar topic as your own, this would be more ideal-but take what you can get. When you watch the talk, ask yourself what makes it good or bad? Were they enthusiastic and sincere? Did they keep the energy throughout the talk? Were there some rough areas of the talk? When nerves are running high, talks may not go as expected. You can battle this nervousness by showing up well-prepared. If you are, the thesis defense talk is just a formality.

If you cannot obtain any thesis defense talks on video, make sure that you go to actual public thesis defense talks. At least go to one so that you have a good idea of how to TIE the whole story together and give your audience the big picture. Keep in mind that you are giving a talk to a general audience. This means that use of jargon and highly technical terms will only put your audience to sleep. Make sure it is clear and understandable. Simplify it the best that you can and put it in the larger context of your research field. Use cartoons or model slides (if necessary) to give your audience the general, overall picture.

3) Have your friends, labmates, and others drill you with questions

What’s the best way to prepare for unforeseen questions? Have others that are familiar with your work drill you with questions. Chances are that even though these questions may not be the actual questions you will be asked either by the public and/or your thesis committee, it prepares you to think on your feet. It also builds your confidence. And the questions that your labmates or friends ask you may just be the same question you will get asked on your defense day.

4) Re-read over your entire thesis and write out your own list of questions

You may be sick of reading your entire thesis over and over by now, but you need to keep everything fresh in your mind. I actually read over my entire thesis multiple times during my final two weeks and came up with my own list of questions that I thought my committee would ask me. In addition, I also came up with a list of questions that I had of my own (questions that I was unsure of or that I thought were a weakness of mine). If you cannot come up with a list of good questions, then you are not trying hard enough.

Even though my committee didn’t ask me my exact list of questions, the process of  coming up with my own list of questions-then finding the answers to those questions (beyond my thesis)-actually helped me gained a deeper understanding of my project. And it was a confidence booster in disguise.

5) Don’t let distractions get to you

Completing your thesis is a huge milestone. Those last two weeks until defense day can be stressful. Whether you are doing job interviews, applying to other jobs, or you want to “jump the gun” and finally start your post-PhD life, don’t give into temptation. Keep your guard up until your actual defense day. This is key to giving a good talk. You need to go in with the mindset that you will kill your presentation and give a long lasting impression to your audience. I have actually heard that some people who gave great thesis defense talks were offered a position shortly after (i.e. a postdoc).

You are going to want to do all those little tasks that you have been putting off for so long because you have spent X amount of months writing your thesis in solitude and you had no time to do them. Your list could be very long. I can tell you that one of the things on my list was to keep publishing blog articles and keep my blog running. I simply did not have enough time. Prioritize and focus on your defense talk and nothing else. If you are looking for jobs during this time period, I will be writing about this in Part 3 of this series.

6) Get plenty of sleep, keep your diet in check, and take care of yourself

This might be the most difficult thing for anyone. I struggled with this the most while writing my thesis. Skipping meals, late nights, overloading your system with caffeine just to stay awake. You have to fight it the best that you can. A month before my defense talk, I hit the gym 3x a week (for the first time in months). Everyone handles the anxiety of their defense talk differently. I am someone who thinks about it constantly. So it becomes hard to focus on other things, like taking care of yourself.

Once your thesis is turned in to your committee members, during those final two weeks- sleep and a proper diet are KEY. The day of your defense, make sure you are well-rested (don’t stay up all night stressing about it) and eat well. Don’t sell yourself short. By taking care of yourself, you ensure that you have the highest probability for giving a great thesis defense talk and showing your committee members that you are confident about your project.

7) Keep your cool and relax

When your defense day comes, you have to remember that you have put in a lot of HARD WORK to get to this point. You know your topic better than anyone. Because of this, you have no reason to be stressed out.

When your committee pushes you and asks you questions, they again will push you to your limits. You will meet a point where you won’t know the answer. Also, a question could simply be a future direction/experiment that you simply haven’t tested yet. Remember that they are simply trying to test your knowledge and humble you. You don’t have to know all the answers. Therefore, when you are answering questions, keep your cool and relax. Answer the questions the best that you can and you should have no problem passing. And in all honesty, the prelim (or qualifying exam) was much harder than the actual defense…

8) Don’t focus on the after-party until you have actually reached the after-party

Who doesn’t want to spend their final two weeks planning the celebration? Although I did have an after-party, I did not go to great efforts to plan it like a wedding party. As I said in #5, prioritize and focus on your thesis defense talk and nothing else. Plan your after-party while you are on break from your practice talk/preparing for questions/working on slides but do not make it a number one priority. Once you have passed, then you can change your focus. The feeling is indescribable (see #10).

9) Have a good structure

A good thesis talk also has a good introduction before going on to the next idea or slide. It should flow in a logical manner and be smooth. That is why #1 is important, because many people don’t spend enough time in the creation of good powerpoint slides. Your slides and talk have to MATCH up, meaning you can’t have really good slides and a mediocre talk (or vice versa) if you want it to go well.

This is why practice is important, and if you spend enough time on BOTH the talk/slides you will give a very good talk. A lot of times while I was actually practicing my talk, I had to go back and change the order/wording of slides or how I introduced certain slides (the wording) so that the flow would be better.

Be formal in how you word things (i.e. say “our data show that”… vs. “you see here that”…). To give a good introduction, it might be wise to use slides that ask a question in between. This question slide (break) in-between your next idea allows for your general audience to CATCH UP and understand your logic. Why are you doing this experiment? If you just show a bunch of your published data with no introduction (and maybe a title that gives an interpretation/punchline), you will overwhelm and bore your audience.

Many scientists forget that although they are an expert on their topic, what seems easy and understandable to them-does not apply to others outside of their field.

Before you go to your next data slides introduce the idea (based on this data I wanted to ask this question). Then tell them WHY you performed this particular experiment (which is basically in the form of a question). Once your audience understands why, go on to the next slide and give them your interpretation. In other words, don’t just jump to the interpretation. This will keep your audience’s attention and make sure that your thesis defense talk gets a lot of positive feedback and leaves a good impression on your committee members (it really does show).

10) Visualize yourself giving your defense each day and think about how good it will feel when it’s over

This one is pretty self explanatory. I will say that when it is all said and done, it feels like a huge burden has been lifted off your shoulders. It is emotional and you finally feel that all that hard work and time that you put in over the years-was all worth it in the end. Good luck to all those who are preparing for their defense talk in the future! Think about what it will be like to get up in front of a large audience and show everyone how you moved a field forward. This is YOUR moment to show everyone you are an expert in your field. The more you keep this mentality, the better your talk will be. Keep your cool and relax (#7) and everything will be fine.

If you would like to see an example video of a defense talk that illustrates the advice I’ve given, a link to my PhD defense can be found here: http://bit.ly/1sAIT7O

Best of luck to all!


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