Dissertation Defense Presentation: A Worked 30-Minute Structure
A worked 30-minute dissertation defense presentation, section by section, plus backup slides, the handover to questions and what named US graduate schools require.
A dissertation defense presentation explains your research question, design, findings and contribution in a set time before your committee questions you. At some US schools it is also open to the public, so it has to work for two audiences at once. Below is a worked 30-minute structure with a sample line for each section, the backup slides to prepare, and how to hand over to questions.
Your graduate school and program set the rules, and they differ. Check the format with your advisor and committee chair before you build anything.
What graduate schools say about the presentation
Graduate school policies say whether the defense is public and how much time goes to questions. Of the three below, Ohio State and Toronto set a length for the talk itself.
| School | Is it public? | What it says about the talk and questions |
|---|---|---|
| Ohio State | A public presentation is allowed | The exam "lasts no longer than two hours"; the presentation is "recommended to last about one-half hour" |
| UNC Chapel Hill | Open, closed or a mix (see below) | It is "primarily a true defense of the dissertation" |
| University of Toronto (Canada) | The chair may admit non-committee members | The candidate summarizes the thesis "in no more than twenty minutes" |
Ohio State's handbook is the most specific about time. It says "At least one hour of the two-hour examination period" must go to discussion of the research and to committee questions. UNC Chapel Hill's handbook says the defense "may be open to the public, limited in attendance to the candidate and the committee, or a combination of the two". Wherever you are, plan on the talk being the shorter part of the event.
Who your presentation is for
A public defense has two audiences: a committee that has read every page, and guests who have read none of it. A good structure serves the guests in the first few minutes, then turns to the committee.
Family, friends and colleagues from other fields need to know what problem you studied and why it matters. Your committee needs to see that you can state your argument, defend your design and claim no more than your evidence supports. If your defense is closed, you can skip most of the plain-language opening and spend that time on design.
A worked dissertation defense presentation structure
The plan below fits a 30-minute slot, the length Ohio State recommends, and finishes 30 seconds early. The dissertation in it is invented for this guide: it asks whether a new bus route changed how often older adults in one city visited a doctor, using clinic records and interviews.
| Time | Section | What the slides show | Sample line |
|---|---|---|---|
| 0:00-1:30 | Opening | Title, your name, committee names | "Thank you all for coming. I'll talk for about thirty minutes, then the committee will take over." |
| 1:30-4:00 | The problem in plain words | One photo or one number | "In 2015, an older adult in this neighborhood needed two buses to reach the nearest clinic." |
| 4:00-5:00 | Research questions | The main question and sub-questions | "My dissertation asks whether the new route changed how often older adults saw a doctor, and why." |
| 5:00-8:00 | What was known and the gap | Two or three key studies, named aloud | "Transit studies measure ridership. Few follow riders into the clinic." |
| 8:00-10:00 | Framework | The lens and why it fits | "I used an access framework because it separates being able to reach care from choosing to use it." |
| 10:00-14:00 | Design and data | Data sources, sample, analysis, one rejected alternative | "I didn't run a survey alone, because people misremember how often they visit a doctor." |
| 14:00-23:00 | Findings | Three findings, about three minutes each | One headline sentence per finding, one chart, and the page where it appears in the dissertation |
| 23:00-26:00 | Discussion and contribution | Findings against the literature; the contribution | "This links a route change to clinic visits for older riders." |
| 26:00-28:00 | Limitations | Two limits and what you did about each | "Clinic records miss visits outside the network, so I checked the pattern against interview accounts." |
| 28:00-29:00 | Implications and next study | One practical implication, one next study | "The next step is testing whether the effect lasts beyond the first two years." |
| 29:00-29:30 | Handover | Your name and "Questions" | "Thank you. I'm happy to take questions." |
The sample lines are illustrations, so replace each with a sentence from your own dissertation. Keep the contribution line word for word the same as it appears in the dissertation, because the committee can compare the two.
The handover to questions
End by handing control back to the chair, who runs the questions. Ask your chair beforehand how the session will run, and rehearse the handover line so you do not trail off.
The order depends on your school. At Ohio State, questions from the public are allowed within the two-hour exam, and the handbook recommends a closed questioning session limited to committee members. At Toronto, the guidance for exam chairs says the candidate and any non-committee members leave before the committee votes. Our guide to what happens at a dissertation defense walks through that sequence.
For a public question, give a short, plain answer and offer to say more afterward. A line such as "The short answer is yes, in two of the three neighborhoods, and I'm happy to show the detail later" keeps the room with you. Save technical depth for the committee.
Backup slides: the appendix your committee will use
Backup slides sit after your final slide and answer questions you expect but have no time to cover. They can be the most useful slides in the deck, because a committee question can be answered with a chart instead of a description.
Prepare one backup slide for each item below. Skip any that do not apply to your design.
- The full model or coding scheme, if your main slides show a simplified version
- Robustness checks, or how you tested whether a theme held across participants
- Your instrument, such as the survey items or interview guide
- The rejected alternative design, with the reason you rejected it
- Sample details, including who dropped out and why
- A finding you left out of the talk, in case a member asks about it
Number the backup slides and keep a printed list of them. When a question comes, you can say "I have a slide on that" and go straight to it.
Adjusting the structure for a shorter or closed defense
The 30-minute plan shrinks by cutting context, never findings. If you have 20 minutes, cut the plain-language opening to one minute, merge the framework into the gap section, and give the findings about seven minutes.
At the University of Toronto in Canada, the guidance for exam chairs says the candidate is invited to summarize the research "in no more than twenty minutes", so the 20-minute version fits there. You will also see the word spelled "defence" in Canada, as in McGill's Doctoral Oral Defence page. For a closed defense, drop the plain-language opening and spend the time on design and limitations.
For how many slides each length can hold, see our guide on how many slides a thesis defense needs. If you are preparing for a UK-style viva instead, the viva presentation structure examples cover shorter talks, and some vivas have no presentation at all.
A rehearsal checklist for the final week
Run the whole talk at least twice under the same conditions you will face on the day. Use this list:
- Time it with a visible timer, and note where you run long.
- Rehearse in the room if you can, with the projector and clicker you will use.
- Test the remote setup if any committee member joins online, including screen sharing.
- Say the handover line aloud so the end sounds planned.
- Practice two backup slides by having someone ask a question that sends you to each one.
- Bring a copy of the file on a second device or drive.
What Thesisroom does with this
Thesisroom does not build slides or write what you say. Defense Practice writes questions an examiner or committee could ask, each tied to a passage of your own dissertation, in three styles: Practice, Rapid round and Mock panel.
Use those questions to decide which backup slides you need. If a question lands on a claim that your talk makes, rehearse that answer and add a backup slide for it. You can find it in the Defense Practice room.
Frequently asked questions
How long is a dissertation defense presentation?
It depends on your program. Ohio State recommends a public presentation of about half an hour within a two-hour exam, and the University of Toronto in Canada sets no more than 20 minutes. Ask your advisor or chair for your program's rule.
Is a dissertation defense open to the public?
Sometimes. UNC Chapel Hill's handbook says a defense may be open to the public, limited to the candidate and committee, or a mix. Ohio State allows a public presentation with questions from the public. Check your own graduate school's policy.
How many slides should a dissertation defense presentation have?
Set the slide count from your time slot, with one idea per slide. Our separate guide on how many slides a thesis defense needs works through the numbers for 15, 20 and 30-minute slots.
Should I thank people during the presentation?
A short thank-you in the opening minute is enough, naming your committee and anyone who made the research possible. Keep longer thanks for after the defense, because the committee's time is for your research.
What happens after the presentation ends?
The chair opens questions. At Ohio State, the public may ask questions and a closed committee session is recommended. At Toronto, the candidate leaves the room before the committee votes. Your chair can tell you the order at your school.
What should backup slides include?
Anything you expect to be asked but cannot fit in the talk: the full model or coding scheme, robustness checks, your instrument, sample details and the design you rejected. Number them so you can find each one quickly.
Sources
- The Ohio State University: Graduate School Handbook, Section 7, Doctoral Degrees
- UNC Chapel Hill Graduate School Handbook: Doctoral Degree Requirements
- University of Toronto School of Graduate Studies: Chairing a Final Oral Examination
- McGill University Graduate and Postdoctoral Studies: Doctoral Oral Defence
How this guide was made: Thesisroom drafted this guide with the help of AI writing tools, then checked every fact, figure and source by hand against the references linked above.