I've been to many PhD proposals and defenses, but I've yet to give either myself. At every talk I've seen, after the speaker finishes his/her presentation and the non-committee members ask their questions, we're asked to leave the room. I assume the committee then asks the speaker questions.

Are these questions any different from normal questions you would get at a talk or do they function as a sort of impromptu oral exam? Do students prepare for them in a particular way or it is just assumed you'll pick up on what you need from your studies and work on your thesis?

  • Some committees use the time to talk about detailed changes to the thesis. Such as things they want to see added, typographical errors, etc. But the practice is not universal, at some institutions all the questions are public until everyone except the committee is asked to leave the room. Commented Dec 11, 2015 at 1:53
  • 4
    It may be different from university to university, so keep chatting with your fellow grad students / alumni and ask about their experience may be a good idea.
    – Greg
    Commented Dec 11, 2015 at 3:22
  • 1
    Just to illustrate that it depends a lot: In my department, we still have to do a so called “Rigorosum”, where the defendant is asked about some mostly random topics from their discipline. In the next university, 25 km away, the defendant may choose between just talking about their thesis and a Rigorosum (which probably nobody ever does). You have to look into the regulations and if they don’t exist, ask somebody with experience. It’s definetely a case of Academia varies more than you think it does.
    – Wrzlprmft
    Commented Dec 11, 2015 at 5:59
  • You are allowed to ask people in your department who graduate before you. In a well run department, any problems that might lead to a failed thesis defense are caught and fixed before it gets that far.
    – user137
    Commented Dec 11, 2015 at 9:02

2 Answers 2


I don't think there is any universal answer to this question. I just defended about 8 hours ago, in my case there was a pre-defense and a defense. The pre-defense in our program tells the student what needs to be done to successfully finish the program, the actual public defense is largely ceremonial. When I met in private with the committee they just shook my hand and that was the end of it.

I am aware of other defenses, where there is an oral exam after the non-committee members exit the room. But, from what I have been told the questions in this exam are largely for clarification, and to determine what needs to be done to graduate.

I'm sure some others can clarify, but usually your dissertation advisor has your back, and you have already done the work at that point. So the defense is more of a chance for you to share your work, than a second order comprehensive exam.

It really depends on your country, institution, department, and program.

  • 38
    I do believe congratulations are in order :)
    – tonysdg
    Commented Dec 11, 2015 at 2:58
  • 4
    "usually your dissertation advisor has your back" — yes! Obviously, s/he doesn't want to have someone go up for a defense and have them fail. I'd imagine in most fields (in the US at least), advisors won't even consider letting you defend unless they feel assured you'll defend successfully. Commented Dec 11, 2015 at 5:17
  • 1
    At my PhD institution, there were reportedly a couple instances where people did fail their defense because their answers to the questions from the committee were unsatisfactory. I didn't get names attached to any of these stories, for obvious reasons, but they're recent enough that they should be more credible than just some sort of departmental legend. So it presumably does happen. Of course the point that your advisor has your back is definitely true.
    – David Z
    Commented Dec 11, 2015 at 5:27

I didn't do anything special to prepare for the non-public questions during my defense. The questions seemed pretty normal, there were only a few of them, and then the committee asked me to leave the room for a few minutes while they discussed me. Then they came out and congratulated me on passing.

This pattern repeated when I was on a committee. I don't know if others are different, but that's been the pattern at 2 US universities in my experience.

Not the answer you're looking for? Browse other questions tagged .