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Bill Gardner / Tips for your thesis defence

Your thesis or dissertation defence is the culmination of your years of hard work. What can you do to make it a big success?


  • Go to defences: The best way to find out what happens in a defence is to make a point of going to several defences before your own. You will likely feel much more comfortable and assured when you see the best and worst that can happen, and take note of examples to emulate and to avoid.
  • Timing: For our department, plan your presentation to run about 20-25 minutes, 30 min. max! Remember, the presentation is primarily for the benefit of the Examination Committee, not for additional people who may wander in to listen--it's not a public lecture!--and the Exam Committee will all have read your thesis. They don't need or want an exhaustive description.
  • Contributions: Don't be modest; be clear on your contributions! If someone asks, "Why should you get a degree?," how will you justify yourself? "I've been here 2 years" won't cut it.
  • Slides:
  • Turn on slide numbering. This makes it easy for viewers to jot them down and then say, "Please go back to slide 23..." With PowerPoint you can press 2-3-Enter and zap right to the given number.
  • Avoid using acronyms on the slides without defining them. Some presenters successfully put the spelled-out version elsewhere on the same slide in small font, so people who don't know the acronym can see the meaning, while not distracting from the main points.
  • Identify slides that you can afford to skip over if you see time is getting tight. Some Exam Chairs will cut you off, so don't assume you can talk forever.
  • Think of some expected questions and prepare some extra slides to answer them (the dry run really helps for this, see next point).
  • Rehearsal: Do a "dry run" with faculty and grad students from your research group. Pay attention to their suggestions for improvement, but realize that "you can't please everyone" and tastes will differ.
  • Paper copy: Make sure you bring along a copy of your own thesis, since numerous questions will take the form "On page 25, what did you mean by...?" or "Table 3-1 is not clearly labelled," etc. You will need to be able to turn rapidly to those references and give a suitable explanation. Do not make the mistake of bringing a later revision of your thesis than the one handed out to the committee! Such things make the defence ridiculous and annoying for the examiners.
  • At the defence

    If your Advisory Committee has approved the thesis as "defensible," you will almost certainly pass and get your degree. Don't worry about that! So what is really at stake?

  • 1. Everyone wants to look good: You want to look smart, your supervisor wants to be proud of you, the examiners want to look insightful and thorough, and the department wants to maintain high standards. You should contribute to all of that, and not undermine it by being poorly prepared, disrespectful, sloppily dressed, late arriving, showing irritation or anger, and so on. Do not attempt to "pressurize" the examiners into giving you a break: "My plane is leaving on Monday" "My new job is starting tomorrow" "I can't afford to pay more tuition." Respect the integrity of the process, and take what the examiners dish out without complaining.
  • 2. You want to minimize your "damage": this refers to how much additional work you have to put into corrections and revisions. At worst, examiners will demand more research and/or experiments, and they will insist on rereading the thesis before they sign off. That could take you weeks, even months! At best, there will be some minor wording improvements, checked only by your supervisor. Ordinarily, you'll be asked to insert or clarify some explanations. If you explain your work well and answer questions well, it is less likely that many or major revisions will be demanded.
  • 3. Taking a philosophical view, whether the revisions are little or much trouble, they will make your thesis a better document . Admittedly, it's possible that no one may ever read your thesis again; but it's also likely that you or your supervisor will write one or more articles based on your thesis, in order to disseminate your work. If the thesis is better because of the revisions, those articles may be more publishable and/or easier to write. If you are continuing in an academic or research career, high quality publications in reputable conferences and journals are extremely valuable to you.
  • 4. Occasionally, a defence will transcend a mundane rite of passage. For this to happen, the examiners must really be engaged with the research and the student, and the "chemistry" will be right. At such times, the questions, the speculation, the theorizing, the discussion, the proposals, the unexpected connections that spontaneously flow can open up fruitful avenues of research and even answer open problems. If you attend even one such defence--let alone your own--you will feel that it was an honour and a pleasure, and that this is what academe is supposed to be about.
  • "Defence" implies "attack." Expect to be attacked, and take a confident attitude anyway. Probably you know more than anyone in the room on your particular topic, so don't feel frightened!

    Answering questions from the examiners:

  • Examiners get annoyed when (a) students don't understand their questions, (b) students don't answer them directly, forcing them to repeat/reword, (c) students blab too much, using up the limited defence time. Annoyed examiners tend to demand MORE REVISIONS, then you will be sorry.
  • Pay careful attention to questions and try to answer what is really asked! If you must, frankly ask, "Can you please repeat that?" Don't let your mouth run on beyond the basic answer, or you may say something flaky that invites more probing. Be aware that an outside examiner with insufficient background in your area may really ask a "dumb question," but you should give a polite answer that doesn't appear to put them down.
  • Don't look pleadingly at your supervisor(s) for help! It's your thesis, not theirs. If they sense you need help, they can ask some leading "softball" questions during their turns, and they always get the last questions by convention. If you look at them anxiously, you may trigger them to speak out on your behalf, which is bad form, makes them look silly, and may earn a rebuke from the Exam Chair. They can advocate your case after the defence is over, behind closed doors while your fate is being discussed.
  • Don't worry about writing down everything people say needs to be changed in your thesis. Your supervisor(s) will keep careful notes of this for you.
  • Will the general audience ask questions? If there is time and the Exam Chair invites them to, they may. But you should not invite them; it is the Exam Chair who is running the defence.

    When the questions are over--typically there will be two rounds, and the Exam Chair may or may not ask some--you will be thanked for your presentation and put out of the room, along with any other audience members. Hopefully, some supporters will keep you company in the hallway, so you don't get too anxious.

    The examiners will then decide, first, whether you have passed, and second, what revisions are required. (In our department, you can pass even if one examiner dissents.) These can be either major --meaning that the examiners feel strongly enough about them that they want to reread the thesis themselves before signing off--or minor , left to your supervisor(s) to wind up. In rare cases, no revisions at all are required, but do not expect that outcome, no matter how wonderful you and your supervisor(s) think your thesis is. During this discussion, your supervisor(s) will advocate on your behalf and clear up any misunderstandings, but they will try to be open to input from their peers who may legitimately disagree with them. If there is an external examiner (say, for a Ph.D. defence), their expert opinion will be taken very seriously, since they were selected for that purpose.

    If things go smoothly this phase may take as little as ten minutes. Eventually you will be called back into the room, most likely congratulated on passing, and then the demanded revisions will be outlined. Most likely, it will be left to your supervisor(s) to detail the revisions. If the examiners ask for more revisions than you wanted, this is not the time to argue and pout. Instead, accept their criticisms graciously.

    Finally, if you truly feel you have been unfairly abused by the examination process--it does happen rarely--talk with your supervisor(s), the faculty member in charge of the graduate program, the Chair, and the Dean of Graduate Studies. Work your way up the chain until someone listens to you. Ask the Graduate Student Union for advice. There will be some avenue of appeal that can see the injustice rectified, so you don't have to become a "victim."

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