Preparing for the Oral Defence

PhD candidates are required to take an oral exam called an Oral Defence (or Oral Defence in American English), which is often called a ‘Viva Voce’, or ‘Viva’ for short.

The purpose of the oral defence is for you to explain your study and its contribution to the field convincingly. You will need to cover the problem or question that prompted your research, the methods used, the findings and their implications, significance or application, and future directions.

This guide provides advice on the following areas of preparing and delivering an Oral Defence.

Preparation for your Oral Defence

Delivery of your Oral Defence

Steps of an Oral Defence

Strategies for Handling Questions

Useful Signposting Phrases

Oral Defence Advice Videos

Preparing for Your Thesis Oral Examination

The Perfect Defence – The Oral Defence of a Dissertation


Preparation for your Oral Defence

  • Plan and organise your presentation
  • Consider how your work fits in with the existing research in your field
  • Practice giving an outline of your research, focusing on clarity and coherence
  • Find out the research interests of the panel; they may ask about these areas
  • Anticipate likely questions
  • Remember questions you are asked in meetings; they may come again
  • Prepare copies of important materials for panel members
  • Ask your adviser what the normal practice is, e.g.
    “Can you explain what happens and what I am expected to do?”
    “How long is the presentation?”


Delivery of your Oral Defence

  • Remember this is not an attack; it is a conversation among equals
  • Keep calm, be polite and smile at the panel
  • Maintain eye-contact and speak clearly
  • Use natural body language
  • Use natural spoken language
  • Explain how your research fits with current knowledge
  • Emphasise key words and ideas, pause to highlight important ideas
  • Use clear linking phrases.
    I’m going to divide this talk into three parts…
    I want to start by …, and then I’ll
    I’d like to move on to…
    This is illustrated by…
    That completes my overview of X, so now I’d like to move on to Y…
    Having discussed/analysed X, I’d now like to move to Y…
    To recapitulate…
  • Listen carefully to questions and make sure you understand what the panel are asking you


  • Don’t read from your notes
  • Don’t make distracting movements, e.g. scratching your head
  • Don’t keep your hands in your pockets or held together
  • Don’t memorize answers
  • Don’t speak in a flat tone
  • Don’t include long, complex numbers; approximate numbers are easier to understand
  • Don’t interrupt the panel when they ask you questions


Steps of an Oral Defence

An Oral Defence often includes a short presentation. If a presentation is not required, the Oral Defence will often begin with a general question such as “Can you tell me about your research?”

In your presentation, you should:

Step 1 Introduce your topic
Use Present Perfect to describe background, e.g. This issue has become…
  • Include general background
  • Identify research gap
  • State research objective(s)
  • Include overview of presentation
Use expressive language to explain importance, e.g. vitally important, extremely beneficial
Step 2 Explain your Methodology
Use signposting phrase to sum up when you finish each step, e.g. Now I will move on to…
  • Explain what methods were used
  • Discuss why they were chosen
Use signposting phrases when you move to the next step, e.g. next I’ll introduce the findings…
Step 3 Report and Discuss your Findings
Use approximation when describing results, e.g. roughly half
  • Give an overall trend
  • Report key results
  • Discuss implications of results
Avoid overusing abbreviations and technical terms
Step 4 Conclusions and Significance
Use positive language when explaining your contribution, e.g. these findings will benefit…
  • Recap main points
  • Highlight significance of study
  • Suggest future research directions, if necessary
Use personal pronouns when discussing your work e.g. my findings, I have found that…
Step 5 End on positive note
Avoid abrupt ending and restate main purpose, e.g. in this presentation, I wanted to examine...
  • Thank audience
  • Invite questions
Use signposting phrase to indicate conclusion of your presentation, e.g. that completes my presentation…


Strategies for Handling Questions

Please click here to see a list of strategies and useful phrases to use when handling questions.


Useful Signposting Phrases

Please click here to see the useful signposting phrases.

It is crucial that you consider how you will connect the key parts of your Oral Defence.

Below is a list of signposting phrases taken from the video: “Preparing for Your Thesis Oral Examination” which gives useful advice on preparing your Oral Defence.

Click here to see the transcript and watch the video

  • There are four areas we are going to explore.
  • First, we explain... Secondly, we provide... Then we suggest… and finally we look at....
Main Body
  • The purpose of… is threefold. First, it… hence… and finally…
  • Let us now look at…
  • Now, there are four possible results… first…, the second …., third…, and the fourth…

Please click here to see phrases that can be used in the main body of your oral defence.

Please click here to see language that effectively connects your ideas throughout your Oral Defence to enhance the flow of the presentation.


Oral Defence Advice Videos

In this section, there are two videos featuring academics with experience in Oral Defence.


Preparing for Your Thesis Oral Examination

Dr. Lilia Sevillano

Learning Consultant

Massey University, Auckland

Here is the transcript:

Hello I'm Lilia Sevillano and this video lecture is about the thesis oral examination. There are four areas we are going to explore. First, we explain the rationale for the oral examination. Secondly, we provide pre-defence preparation tips. Then we suggest what to do at the actual examination, and finally we look at the possible outcomes of your defence.
Gives outline of presentation
First and foremost, keep in mind that the oral examination is not the Spanish Inquisition. The examiners are not out to get you. The oral defence or oral exam, also known as the viva voce, is required of all PhD candidates in New Zealand universities. Some Estoril degree students may be required to undergo this as well. But it is not compulsory as a general rule for them.
Highlights key aspect of topic
The Rationale
The purpose of the oral defence is threefold. First, it provides the opportunity for academic conversation among peers. You are expected to provide authoritative insight into previously uncharted or contested issues. As the expert, you are more knowledgeable in the specific area you study than anyone else at the table. Hence, you should be well-prepared to present information persuasively and articulately. The oral defence also allows you to formally disseminate your research findings. Remember that you are sharing valuable information on new scholarship that has the potential to contribute to the advancement of knowledge within your field. Defending your thesis consists of answering questions meant to probe your deeper awareness of how you carried out your research. And finally the oral examination signals the time to bring closure to your doctoral program and to celebrate your enhanced knowledge and expertise.
Gives overview of main point and then explains it
Preparation Tips
Let us now look at some pre-Defence preparation tips. Remember that good planning and organization are the keys that will give you a sense of control at the oral examination. This will not completely eliminate stress but will reduce it greatly. If it is possible, check out the room or venue where the defence will be held. Acquaint yourself with the layout and the data equipment you will use for your presentation. Familiarity with the venue will alleviate any unnecessary anxiety. Decide exactly on what to wear to the Defence. Your clothes should reflect the statement that you are ready and professional, but ensure that your clothes are also comfortable. Almost every Defence begins with a request to give an overview of your study. It is helpful to prepare an outline. A short presentation of 15 minutes of the major points of your research.
Uses signposting phrase “let us now look at…” to indicate a new point
These include a description of why the problem was important, and how it arose, what others have done, the methodology used, the results of your investigation, and the contribution to knowledge, and any implications for the future. Before the defence, do touch base again with current studies underway and related to yours. This is impressive and shows further evidence of your continued interest in research. Have a working copy of your thesis in a loose-leaf binder. Have divider labels for each chapter with summary notes taped to each divider. Knowing you will be able to access information quickly will help reduce stress and it will look neater. Practice your presentation alone and in front of an audience. The clearer your presentation is, the more unlikely you will be asked unrelated or inappropriate questions at the actual defence. Based on a clear and coherent presentation, any intelligent person should understand what you did, why it was important, what you found, and what your conclusions were. Do expect a defence to last from one to two hours on the average.
Uses linking words e.g. “these”, “before”, “this” to connect idea.
The Defence
At the defence, listen, respond and zip it. After your 15-minute presentation, questioning from the panel begins. Try to relax and go with the flow. You can generally expect questions in the wider field and the more specific questions in your research area and the areas of your work that interest the panel. A robust defence is expected of your claims and conclusions that give it your best. Frequently, leading questions may be asked to see your response. Do not be offended but assume a polite, friendly, confident, and professional attitude. Take time to think about the questions. Say “that is a good question”, flattering the examiner, and suggesting you have thought about it already, and buying yourself time to think. Taking time over answering questions allows you time to marshal your thoughts and gives the impression of thinking carefully about the answer. If you do not know the answer and this can happen, keep calm. Provide the best answer you can based on what you know. It is okay to say “I don't know.” However, this should be rare in the defence and not happen too often. Listen well to the question and let the panel state the entire question. Then answer the question and stop. Why? In your enthusiasm, do not get led into elaborating your findings into generalizations your study and data can't support. The defence may bring out suggestions for revision and improvement. Respond to these in a positive way, and take notes as examiners make suggestions.
Once the defence has concluded, you will be asked to step outside for a few minutes while they deliberate the outcome. Now, there are four possible results and these are: first, major revisions withholding approval. This requires that a lot of work be done first before approval is given. The second outcome is that it is approved with minor revisions. Third, it is approved without revisions. And the fourth outcome; approval denied. Now it is very rare that the last to happen, so you can expect either one of the first two possible outcomes to occur. Once the results are out, thank everyone for their help. If there is some preparation, it is unlikely the final oral will hold any great threat. The final defence becomes what many faculty hope for. A lively and informed discussion of an important problem and field of interest in which the candidate and faculty participate essentially as colleagues.
Uses signposting language to guide reader through main point
I hope this has helped you to gain a better idea of what is expected at the oral examination and to prepare for it. Good luck.
Ends on positive note


The Perfect Defence – The Oral Defence of a Dissertation

Dr. Valerie Balester

Executive Director of the University Writing Centre

Texas A&M University

Here is the transcript:

I'm Dr. Valerie Balester, I am the executive director of the University Writing Center. I am an English professor with a specialization in rhetoric and composition, in other words, in writing. I was thinking about it before today. I have been on at least 60 or probably 75 defences, and not all in English: in English, in education, in linguistics, and then also in engineering, in architecture.

We used to have somebody from outside of your home department, sitting on each dissertation defence, as what they call them: a graduate committee reviewer, to make sure that the process went smoothly. So I did that for many different areas. I think many in the sciences and engineering. So I'm very confident about the structure of a dissertation defence.

I'm wondering what you know about the structure of a dissertation defence. Anything that you know at all about it that you could tell me? What do you think happens in that little room? You go with your committee into a little conference room usually, right? Sometimes it's open to the public, and sometimes--I mean, technically it’s always open to the public--but whether you announce it to the public or not is going to determine whether people come or don't come, and in my department, in English, it's not customary for the public to ever attend. If it's open to the public, there is a point at which they will leave, and you will be sitting alone with your committee.

So, what you're doing here is you have to muster up all of your confidence now. This is about confidence. Okay? It's very important and you have to present yourself as a scholar in the discipline and authority on your subject. You have to show them what you have to offer as a scholar, and that's really what it's about. Nervousness is probably the biggest problem, but I’ve seen all of them work through it. I've never seen anyone fail, and have only seen one person ever fail a dissertation in all of those defences. Only one person didn't pass, so your odds, one out of sixty, your odds are good, you're going to pass. So go in there with that impression. The person who didn’t pass wasn't prepared and hadn't talked to his committee beforehand. So, you are most likely going to pass this.

You're going to be expected to clearly and cogently explain your work, and explain how your work fits in with your discipline. Where's your place in this big conversation that's going on in your discipline? What have you contributed to the field, because a dissertation is supposed to be an original contribution to knowledge. What have you contributed to the field? What more needs to be done? That's the kind of thing they're interested in.

So it's not really a grilling. And in your head I want you to turn it from a grilling, because really I’ve never seen when it is a grilling, and the word grilling means where they put you on the grill and cook you until you're finished. It means where they ask you this, this, this, tell me this, do you know this, do you know that, you know, where they just ask you lots of questions, like a big--it's usually not that, it's usually conversation among equals. They're trying to see if you can function as an equal with them now. It's their first opportunity to say you are now an equal, please come in and give me some information, but as an equal, I expect you to be able to explain your ideas, defend your ideas, tell me where your ideas fit in, because they expect it of each other. They're not asking you to do anything that they don't do with each other, and that's why you shouldn't worry. If they suddenly stop talking to you and start talking to each other--that's a good sign actually--that means that you have stimulated their brain. This is what these people live for, they're academics, and they like that.

Sometimes they get into arguments with each other. It's okay and your chair should gently bring that back. If your chair doesn't do it, just let it go, let it happen. If they disagree with you, they expect you to come back with a defence and that's where the word "defence" comes from.

So, you need to know what the rules are. Have a talk with your advisor, and find out. If you don't know now, you can talk to other students, but you definitely need to talk to your advisor a good while before the defence, and say, "I would like to know what to expect. Can you explain to me how defence happens in our department? What is the usual thing that happens? What do you want from me as your candidate?", and then know your committee as well. Sometimes when we work on a dissertation, we get isolated from our committee. Make sure that the committee gets the dissertation in plenty of time--that's something your advisor can tell you. If you give it to them two weeks before, they'll probably read it the night before, and then any objections they have they didn't have chance to tell you about. So if you can give it to them like a month before, even more, you can work that out with your advisor, but the sooner they get it, the more time they have to respond to it and to let you know before the defence, where are their areas of concern. If you go in then and meet with them, but you get your… I think you should get your committee chair’s advice and permission before you go meet with all your members. But when you do that, they even sometimes tell you what question they're going to ask you or maybe they'll give you a hint about what question, because they'll tell you: "What concerns me about your work is this," “what I like about your work is this," "I see this, but did you do that?". And then when they read it again, their minds are going to go back, and "oh we had a conversation, we talked about this, I’m gonna ask the question I'm going to ask". Because when I'm a committee member, and I'm sitting there on the hot spot and I have to ask an intelligent question, I'm gonna go back to what I remember most about your dissertation.

Now the first thing you should be able to do is answer the question: tell me about your dissertation. This will come in handy on the job market as well. So, in your head write a speech, just a brief speech, and you can break it up so that you're basically repeating what’s the information in your abstract. This is the question or problem that led me to research. This is the method I used, the way that I decided to, to deal with that (I should have added a method in here) this is what I found, and I put the thesis separate from here. Thesis is really, what is my hypothesis? This is the problem and this is what I think is gonna happen, then this is what I found happened. In the humanities, we're gonna call it a thesis, and in Sciences we might call it a hypothesis, but I had a question, here's how I thought it would be answered and here's how it actually was answered. And then, this is the significance of my work: how it can be applied, what it means for the profession, how it changes our theories, how it changes our practices, whatever the significance might be.

And don't forget to bring a copy of the dissertation with you to the meeting, because people will surely, usually the committee brings their own copy. Again, that's a thing you want to check within your own department: will they bring their copies, or do I have to provide copies for everybody? But usually they bring their own copies and they'll say: "on page 55, you said blank, blank, blank… explain it." Then you need to have page 55, so you need your own copy, minimum.

Try not to wait until the last minute. If it's not finished, say here's what I have so far. Just put a deadline date and say I don't have everything finished, but here's what I have so far. That gives them the opportunity to respond, and you'll know and they are gonna say, "oh, but you don't have this," and then you're working on it, so be ready to answer about it.

So you have to practice, just like the little girls doing ballet, you need to practice. So, write down, just so you have it in your head, how you would answer the question: tell me about your dissertation. And then practice it. Practice in front of a mirror, say it out loud. Don't memorize it, because you want to be agile. If somebody interrupts you, you want to remember where you are. You don't want to be just rote. You want to be able to say it even in a few different ways, but you want to be able to say that. You get so focused on what you're doing, you want to talk about the details and you forget that other people don't even know what question you're trying to answer. What brought you into the research interests people. What's the problem? How did you approach the problem? What did you think you were going to find? What did you find and what does all this mean?

Of course you want to dress for success, and you want to stay calm, and you want to smile. It's important not to be too serious. To show that you can do this and you can do this, remember the success rate is high. In some fields, it's optional to present, and in some fields it's always done.

First is prepare for technical difficulties. If I came in here today and this was not working, I have my handout, so I could use that. For yourself, if your slides are reminding you what to say, make notecards or make a copy of your slideshow, so you see every slide so you can follow along. Be ready for technical difficulties. It could be that you are in a room where there's never a failure, and the electricity goes out that day, and you have worked a month to get all these people into the same room at the same time--it's not easy to schedule a defence, because every professor has a different schedule and they are all very busy, so you're gonna have it even though the electricity is out. Okay? So, be ready.

Consider handouts. you don't want to give everybody lots and lots of handouts, just to give out handouts. Because you don't want them looking at the handout, you want them looking at you, you want them looking at your slides. So make sure your handouts are only used to present things that can't go on a slide, that can't fit on the slide, or things that you really want them to remember. maybe it's a photograph or an illustration. Maybe it's a chart or a graph, maybe it's a quote. But whatever it is, it should be things you want them to take away with them, to remember, to be very vivid or things that are hard to put on a slide.

Find out how long the presentation usually is. Typically, they're eight to ten minutes. In many cases you're going to need time for questions. In other cases, no, because you're just presenting to the committee and that's just what they're going to do. They're going to start with questions as soon it's over. So find that out from again from your advisor; ask how much time do I have to do the presentation? do I have a public audience? If I do have a public audience, how much time should I give them for questions? It's usually five minutes for questions approximately. So if they say you have ten minutes total, it's five to talk, five for the questions.

We have a handout in the Writing Center called "Designing Effective Presentation Slides" and it's under oral communications, so I suggest you look at that. You want to be sure you don't put too many words on the slide. Make sure your slides basically cover your main points, but that people are looking at you as much as they're looking at the slides. The slides help them if they lose their place. The slides emphasize your main points, but they should be listening to you, not just reading the slides. So, I recommend the handout "Designing Effective Presentation Slides." That will tell you how to divide your presentation, how to organize.

It's the same thing I told you to memorize: the problem or questions that led to your research, your methods for answering the question or solving the problem, your major findings, the implications, significance, or application of your findings. And add to that, your next step in your scholarly career. They'll be interested, if you don't say, they'll probably ask at least. They might want to know if you've applied for any jobs, but when I'm talking about your scholarly career, I'm talking about your research part: what will you research next? Will this dissertation lead to articles? Will it lead to a book? Will it lead to another grant? Another research program? So, where will this take you from here?

The chair will probably say, "okay, we are going to ask you to leave the room." They're just deciding what procedures will be followed, so everybody agrees on the procedures. If they're gonna be allowed to interrupt each other with a follow-up question, or they have to each wait their turn, that's all they're deciding now.

And the next thing they're gonna do is have you come back in and your chair will tell you, “okay this is what we're going to do: we're going to start with Dr. Balester--" and now Dr. Balester has to sound very smart, give a really good question, right? And sometimes in the process in her head, she is still forming the question. So she may ramble on a bit. That's why you have to listen. Listen, really focus, don't be thinking about what I'm going to say next, listen to what they're saying now. Because then, she's going, "well in chapter three, you did blah blah blah blah... And in chapter seven you said la la la la... And then there's a contradiction here, but I kind of think that if we bring in so and so scholar, this might resolve the contradiction and…" and she keeps going on and on. And you're like, “and you wanna know what? What is your question?” And she might say, "and what do you think of that?" So you have to be listening closely. Now you don't know what she said, so what do you do?

Ask her to clarify or repeat the question or you clarify, you say “I think I heard you ask… is that correct?" Okay, now what happens when you don't know the answer? So you have lots of options when you don't know the answer, but I came up with a few options. You asked me whether I think that this is a regular phenomenon. “I'm not sure, but I think...” So you don't have to go: "yes, it's a regular phenomenon”, “no, it's not a regular phenomenon." You can say "I'm not sure," but take a stab at the answer, try to answer. And let them see your thought process. That's what they're doing for you. They're letting you see their thought process when they're going on and on, so you do the same thing. They want to see that you can think. That's what they're looking for: can you think? “Is this a regular phenomenon?” “I don't know, but that question has interesting implications. For example, if I knew the climatic changes in August, then knowing that would help me do this." Keep yourself focused on your data. You are the expert on your data, on your project, on your ideas. You are the expert and they're actually trying to treat you like the expert. They want you to answer like the expert. They respect you, believe me.

There's never any perfect data, so the data are saying “man if I only could have done this”, so that's good to talk about. Be confident however. Say: "given the constraints I was working with, this was what I was able to do. But if I could do more, if, you know, this is my dream, if I could really have done this," or "in doing this, I learned a problem with this kind of data collection. Next time I'm gonna do it this way." Is it okay to just say I don't know? It's okay if you really don't know. This may be a little better. It's better to say I don't know than to fake it. The thing you don't wanna do is fake it. These are not people that will be fooled. So don't fake it at all.

Sometimes when they ask the questions and they're coming and coming, and you're trying to listen. You need a little time. You can slow things down. You can slow things down by pausing, take a breath, look at your notes, even state, "and you think this is a regular phenomenon?" “I need a little time to answer that, can I just have a minute to gather my thoughts?" They'll always say yes. Don't take three minutes, but just a few seconds. Maybe at that point, look down so that you're not distracted by them.

Focus, focus, okay? I can answer this question. Boost your confidence, and then go for it. Another thing is to ask them to repeat the question both when you don't understand the question and when you need a little time. Maybe you did understand it, but you just want to slow things down.

So if you have said something wrong or you realize that you started answering a new question, and suddenly "oh, I should have said that too." How do you handle that? Well it's a good idea to just admit it: "Oh, wait a minute I'm wrong about that, aren't I? I realized that just now." Just correct yourself. Or you can finish answering the question you're on, and then go: "May I also add something else? I realized that when you asked me this, I answered, but I could have said something more," and just go ahead and say it. So you have the opportunity and you have the right to say "I want to say something more I want to correct it. Thank you for that question, I wish I had thought of that earlier, that is a really good point.”

So at the end, they finish asking you questions. They ask you to leave again. Don't go too far, go outside, now you are really sweating. Remember the odds, you're going to come back in and they're going to say, "congratulations!"

“Now, we want you to rewrite the conclusion. However, you have passed, okay?" So, just remember it is very common that they will ask for revisions. They did for me, in fact, one of my committee member said: “Valerie, you know that conclusion just won't do." That's okay, because I managed to pass the defence part, they knew I knew what I was talking about, but they knew that my writing fell down in the hardest part. The conclusion is usually the hardest part where you have to think about the significance and fit it into the, all the literature that you've done. So it's very common for that part, or it could be that you have some tables that are not in the right format, or it could be something else they noticed that some problem they thought that you just did not quite capture. Sometimes you said something in the defence, but they want you to put into the dissertation. Usually when you come back into the room and they say you passed, but we want you to make the revisions, they expect your chair to keep notes, and he or she will actually make sure you make the revisions. However, you could also suggest at that point when they say “we're gonna need revisions”, you can ask them, “could you please summarize the major revisions you want for me to make so I can make some notes now?" Now, whether each committee member is going to have to see those changes or not will also depend on what they decide with your chair. Many times they decide that the chair will be responsible for making sure those revisions are made and they don't have to see it again. But you know they still have to sign your dissertation. So sometimes they'll sign it there if you take your title page in with you they will sign it right there, and sometimes they won't sign it until they see those revisions. So that's another reason, you go see your chair to find out how it's normally done.

At other times, everything is fine, they don't even want any revisions, and as I said, it's possible they will say you did not pass the defence. Knowing your material is extremely important. Don't go in there without having read your own work. You think you've read it, because you wrote it, but you haven't read it. Even if you finish writing it a week before, give yourself a little time, and read it again. Practice and knowledge of your topic will make you feel really confident and positive self-talk, remember who you are. You probably know more about this topic than anybody. I can guarantee you know more about this topic than anybody, even more than your advisor, okay? Because that's what a dissertation is: it's going farther than where your advisor can take you, you have to go rest of the way. So hopefully even though your advisor is going with you, and following behind, you really do know more if you stop. Think a lot before you get there, that's why you need the time to prepare it. Read your dissertation though.

I really appreciate that you came today. You can always reach me at the Writing Center as well. It's Valerie Balester, and if you go to "About the Writing Center”, you'll see the staff directory and my email, okay? So if I can give you some confidence, let me know. Thank you.