Science private defense

October 8, 2010 9:27 PM

If you gave your science PhD defense in the US, tell me all about it!

1. As a student, how did you survive it? Emotionally, lifestyle changes, preparation, everything! How long before the defense did you start the *preparation*? I am not sure I really know how to *prepare* for it, even though I have talked to a number of people. It just seems so very broad and vague that the prospect of having to go through it is scary.

2. If you are a faculty member, how did you survive yours? If you were on a committee as faculty, what makes the defense a success or failure (in terms of your expectations, not in terms of getting the degree)? And what are your expectations?

(Anecdotes of good/bad experiences are welcome!)

I have also noticed some faculty talk very critically (seemingly unfair to me) about some of the previously "good" students afterward. It's hard enough to navigate this without really knowing the expectations than also having to deal with the gossiping around as well. This makes the prospect of having to go through it even more unsettling.

3. Even though I mostly enjoy presenting, especially when a larger audience is present, I am very shy. Being grilled by six experts in a closed room for two hours is not something I look forward to (but I get excited about presenting to 150 or so strangers in a conference hall!). I also have short attention span/get bored easily. After the presentation, I just cant wait to get out. I know #3 is mostly mental/personality thing but it skews the whole perspective. I'd like to hear from anyone who had these problems and was able to get over it.

Thanks in advance!

posted by xm to work & money (19 answers total)

In many departments, you would never let a Ph.D. student defend unless they were certain to pass. Find out if yours is one of these. If so, your stress level will be lower.
posted by escabeche at 9:31 PM on October 8, 2010 [3 favorites]

What escabeche said.

Maybe I'm overgeneralizing a bit, but if your department is anything like mine, if people did fail their defenses you'd probably have heard about it. If you haven't heard defense-failure stories, then your department is of the sort escabeche describes.

I wouldn't describe my defense as a "grilling". I talked for about forty-five minutes about my results (the hard part here was getting the presentation down to 45 minutes, because I could have talked for hours!) A few questions were asked, maybe ten minutes or so? It really felt very similar to the sort of presentation I'd given several times before about my work, with the exception that there was this annoying bureaucratic form that three people (my committee) had to sign afterwards. (They freaked me out by taking forever to sign it; apparently they just started talking about my work, which they found interesting, and forgot that I was sweating it out.)

But really, the moment I knew I would pass was when my advisor was excited to see that I'd brought cookies. (Note that you don't have to bake cookies. Chips Ahoy are perfectly acceptable.)
posted by madcaptenor at 9:42 PM on October 8, 2010 [2 favorites]

(It should be noted that escabeche and I are both mathematicians. You appear to be a life scientist. The customs may be different in your field.)
posted by madcaptenor at 9:45 PM on October 8, 2010

I had to defend my MS thesis last year in the US. I'm guessing your experience will be a lot like mine, only longer and with more detailed questions.

Do you have to do a public presentation before the questioning starts? I had to present my research to whomever showed up on the day. Usually no one in the department bothers, but for some reason the whole faculty and most of the students showed up for mine. I went into this pretending it was a conference talk: structure the presentation to explain the research to an informed audience, PowerPoint slides as needed, extra slides at the back to answer/illustrate anticipated questions, etc. There were some general questions from the crowd and then everyone left, apart from my committee, who then asked the more detailed questions.

My thesis advisor's (very excellent) advice for how to prepare for this was "remember that you are the expert here." You have spent a number of years doing research, running experiments (I'm guessing), collecting and analysing data, presenting findings, and writing it all up. You have been living and breathing this project for a long time and should be in a position to answer any question about what you've done and why. Someone could trip you up a bit by asking about why you didn't do something (i.e., some extra analysis technique, additional samples, etc), but see the previous sentence. You know your project. You are the expert here. Furthermore, your research design (presumably) has been vetted along the way by your committee, but they have to ask you something. And some faculty like to make people sweat.

(Honestly, I was shocked at how easy it all was. One of my committee members was simply pointing out typos.)
posted by Eumachia L F at 2:18 AM on October 9, 2010

Another faculty here, but probably not in your discipline, and certainly not in your department.

1. I agree completely with escabeche and madcaptenor.

2. When I came to defend, I had already been offered a postdoc. I didn't stress at all about the defense because I figured if my job talk was good enough to get a postdoc, it was probably good enough for a defense as well. In the current job climate, you might not be as lucky as I was, but if parts of your thesis have already been published, you can use them in the same way. (I.e., "If this work was good enough to get into X, then surely...")
posted by sesquipedalian at 2:45 AM on October 9, 2010

In my defence for my PhD what I was most struck with is how matter of fact everyone was. Essentially they took turn asking me very picky questions about what exactly I had written, and pointing out spelling and grammar errors, and not talking about the science at all. Honestly I wouldn't worry about it at all, because by the time you are ready to defend you are the world leader on that specific subject, so even if someone throws a question that you have never even thought about chances are your advisor hasn't thought about it either and they already have their PhD. You can't try and do everything, you just try and answer what comes up the best you can and be receptive to new ideas. You advisor will probably like the oddball questions because they might lead into a more interesting area of the project.
posted by koolkat at 2:50 AM on October 9, 2010

Defense format:
Hour talk with public and committee present followed by questions by my committee in a closed room. I spent about a week preparing this, mainly because I only had two weeks to write my thesis. After the talk, the audience was asked the leave the room and my committee asked me some questions about the work - most of these questions were matters of clarification, there were a few general questions but nothing impossible. As with my preliminary exam, I tried to make this into a conversation rather than an interrogation.

I practiced the talk ahead of time and went over it with my advisor to make sure he was happy with it. I'd suggest a few rounds of practice talks - the final practice talk ideally at lab meeting and try to include a couple of people not in your lab so they can ask the kinds of questions that someone who isn't immersed in your research area would ask. Remember to thank your advisor and committee at the beginning and end of the talk.

They won't let you defend unless they think you're ready. The people asking the questions are the ones who have been hearing about your work at committee meetings for a couple of years now, so they're pretty familiar with things and you should be fairly familiar with their areas of expertise and thus what kind of questions they are likely to ask.

Most defenses are formalities.
posted by sciencegeek at 5:00 AM on October 9, 2010

n'thing everything said. Your advisor wouldn't let you defend if he/she didn't think you were ready.

My defense (theoretical chemistry represent!) was nerve-wracking, yes, but that's because of my own stage fright (which I didn't help asking a Nobel Laureate to be on my committee...). Like sciencegeek, mine was an hour long talk about my research with a general audience (pretty small since, well, my research wasn't that exciting) followed by, oh, an hour or so of questioning from the committee.

The questioning wasn't bad and, in truth, it shouldn't be. Remember, aside from, perhaps, your direct advisor, you know more about all this than anyone else in that room. Most of them will have "read" your thesis, yes, but that's read for various levels of "read". Some might skim it, some will come with post it notes sticking out of the binder, but you did this work so you know it. The only difficult questions will be those ones that you already know are difficult (future paths for the research, what would you propose to help bolster your arguments, etc.)
posted by Fortran at 5:25 AM on October 9, 2010 [1 favorite]

Being grilled by six experts in a closed room for two hours is not something I look forward to

As far as getting your self-confidence up, I think the trick is to stop thinking that your committee members are the "experts" in the room. True, they're established scientists with years of experience. But YOU have been obsessing about the details of YOUR research for years now, and you know the details of your topic better than anyone else in the room. You probably know more than you think you do!
posted by JumpW at 5:41 AM on October 9, 2010 [2 favorites]

I don't know if it'd help you any, but here's a video of my defense.
posted by dmd at 6:28 AM on October 9, 2010 [2 favorites]

I met individually with my committee members quite a bit to find out what was required before we even scheduled the thing. That helped considerably with my comfort and confidence. The level of grilling was much less than in my qualifying exam a couple of years prior.
posted by exogenous at 7:23 AM on October 9, 2010

I sat in on a couple computer science defenses at MIT and the actually seemed kinda proforma. There was quite a famous professor (AI) at one and there certainly was nothing like grilling.
posted by sammyo at 8:08 AM on October 9, 2010

My defense (in biochemistry) was simply a seminar presented to the whole department, with the usual Q&A session afterward. A few committee members asked questions just to prove they'd been awake, but that was it. The thesis defense is usually a lot less stressful than the oral qualifying exam - if you pass that, you're going to make it all the way through the program. The orals are where they wash people out, not the thesis defense. (Could you possibly be asking about the oral exam, instead of the defense, if you're not familiar with US academia?)
posted by Quietgal at 8:57 AM on October 9, 2010

Same here with my biology PhD, a seminar presented to the whole department, with questions afterwards. I wasn't worried. Writing the thesis was hard, but I was done with that. I knew all about the topic after that.

There was one bit of special preparation I remember. I'd been depressed by my last year of thesis writing, so much that I could not drink alcohol during that time. It lowered my inhibitions against noticing how miserable I was. Since I hadn't been drinking, my alcohol dehydrogenase levels were way low, too low to allow for much drinking of champagne at the party after my thesis defense. I needed to go into training. Once the thesis was turned in and I knew all was well, I made sure to drink one or two ounces of alcohol every night. By the time the defense came around I was ready. I was able to drink quite a few glasses of champagne without regretting it.
posted by Ery at 9:33 AM on October 9, 2010

Just in case you haven't decided this yet, at my institution in the biological sciences defenses are also pro-forma. I haven't been to one where the champagne hadn't already been purchased. Your advisor and committee chair will have read your work before they agree to let you defend. Your last committee meeting should have approved you to write. It would be humiliating for both these people if you failed, so they will have made sure that there is no show-stopper. People fail out of / leave grad school all the time, but not at the defense.
posted by a robot made out of meat at 12:48 PM on October 9, 2010

Thanks all for the responses.

I am looking more for what did you do/not do weeks/months before the private to prepare for it rather than "you dont have to worry coz they wouldnt let you defend if you werent ready" (I agree with this). I understand my words probably veered the responses to the latter but I was looking more for tips to "get through this last phase" and not break down before/during it (think marathon!).

Also, since this has come up, I do know of a person who had to give the private twice!! Can't remember why though.
posted by xm at 5:53 PM on October 9, 2010

Honestly, in the time leading up to my defense, the only thing I did was make slides and run through them with two groups of people: labmates/lab group, and grad student friends who only knew tangentially about my work. The rest was just logistics--does your computer work with the projector? Is your suit clean? Did you tell friends/family the date and time, if they want to see the defense? Is everything spelled correctly on your slides? Have you read through all the university and department guidelines and followed them? (My defense was immediately followed by dropping off paperwork and thesis copies at three different campus locations, all due the day I defended.)

To be fair, my department was structured so that the defense couldn't even be scheduled unless a bound thesis was on the graduate administrator's desk, so I wasn't trying to balance defending with writing. However, I feel it's pretty reasonable to just treat it like a long conference talk with a particularly in-depth Q&A, and prepare for that. (It was certainly a formality in our department; one professor who'd been there since his grad student days noted that he'd never actually seen someone fail in 20-30 years. Champagne and cookies are prepped ahead of time. Our department gets its "weeding out" out of the way during second-year qualifying exams instead.)
posted by Upton O'Good at 12:50 AM on October 10, 2010

Upton O'Good says "is your suit clean?" That's actually a good question: you should find out what people typically wear to their defenses. I don't remember what I wore, but it certainly wasn't a suit. Had I worn one, they might have failed me for showing that I clearly hadn't spent enough time among mathematicians to realize that they don't wear suits.
posted by madcaptenor at 8:29 AM on October 10, 2010

On getting through the last weeks:
No one on my committee actually read my thesis. Your prose doesn't have to be sparkling, just comprehensible.

Making figures always takes five times as long as you expect - if you don't have experience with the software, try to use a software that you do know well.

Get someone you trust to read your drafts (both of the written thesis and of the slides for your presentation) and help you make things comprehensible.

As mentioned by others, make sure you have a comfortable but professional outfit picked out so you don't have any last minute surprises.

Remember to eat and sleep. Get help if you need help.
posted by sciencegeek at 10:23 AM on October 10, 2010