Preparing for your thesis defence

The thesis defence is a unique opportunity to share with other experts what you did as part of your PhD research, what you found or discovered, and why it’s important. Although there are a lot of regulations guiding the defence process, remember that this process is really about you and your work.  

Goals of the PhD defence:

• Allow you to show your mastery of the subject matter
• Prove you are the author of the world
• Demonstrate your ability to engage in scholarly discourse in your research area

The primary attendees of your PhD defence are the Chair of the defense and your examining committee. The Chair is an impartial faculty member from outside your department who is well-versed in the rules and proceedings of thesis examinations. The Chair does not question you and does not assess your work.

Examining committee:

• Supervisor(s) - Your thesis supervisor(s) that have supervised your research.
• Internal member - A member of your department; typically part of your advisory committee.
• Internal/external member - An "internal" member of the university, but "external" to your home department. This person has suitable knowledge of the subject matter, even though they are from another discipline.
• Additional member - Typically a member from your advisory committee.
• External examiner - A person with a doctoral degree and expertise in the subject matter who evaluates the thesis from a fair an impartial perspective.

At University of Waterloo, it is also standard to have defences open to the public, so you can invite your friends, family and colleagues to be there! Check with your department to figure out what options are available to you.  

In some cases, such as when there are intellectual property concerns, a closed thesis examination can be requested. This means that all those in attendance at the thesis examination, including the examining committee members, must sign a non-disclosure agreement.  Closed examinations must be requested as early as possible.

The first component of the defence is the welcome. The Chair will open up the defence, go over the order of proceedings, introduce the examining committee, and welcome the attendees.

After the welcome, the examination will formally begin with your oral presentation. The presentation is no more than 30 minutes, but the exact length and format can vary by department or discipline. It's best to check with your supervisor to confirm departmental expectations, but overall, the presentation should focus on your main contributions and conclusions. 

The final component of the defence is the questioning period. This is not meant to be an interrogation, rather, a discussion amongst colleagues about the subject of your thesis.

• The examination Chair monitors the question period, which goes in "rounds".
• During the first round of questioning, each committee member will have 15 minutes to ask their questions, provide their comments, and discuss these with you.
• After each committee member has had their turn to ask questions, there may be additional rounds for more questions. The Chair and committee decide when the questions will end.
• Typically, the Chair will reserve some time at the end to accept questions from non-committee members.

While there is no set time for defences at the University of Waterloo, they typically range from 2-3 hours. 

Once your formal defence has concluded, the examination Chair will arrange for a private deliberation between the committee members. The examination committee's decision is ultimately based on your written thesis, as well as your ability to defend it, as the decision is determined by a majority vote.

In the event of a tie decision, or if the external examiner's vote is not in the majority, the decision will be deferred to the Associate Vice President (AVP), Graduate Studies and Postdoctoral Affairs. The AVP will consult the Faculty Associate Deans and come to a final decision. 

Once the deliberation has concluded, the Chair will inform you of your examining committee's decision.

There are three possible outcomes to a PhD defence:

1. Accepted: The thesis is completed to the satisfaction of the examining committee. There may still revisions required, but they are likely minor and typographical or editorial in nature. In this case, you would have one month to complete all revisions and submit your approve thesis to UWspace.
2. Accepted conditionally: The oral defence and the thesis are acceptable, but content changes are required that are time intensive. In this case, you would have four months to complete revisions to the approval of your committee and submit the final version to UWspace. A re-examination is not required. 
3. Re-examination: The oral defence is not to the satisfaction of the committee and/or substantial changes to the thesis are required. In this case, the candidate must be re-examined within 1 year. 

Re-examination is very rare, and the vast majority of candidates have their thesis accepted at their first examination.