The defence is similar in structure to the candidacy exam, but formalized and expanded. The defence lasts no more than two hours, with an examining committee consisting of:
- The supervisor
- Supervisory committee members
- Internal-external examiner
- External examiner
At present, all physics and astronomy final defence exams are open except for the deliberations. At the appointed time, the exam will commence and the candidate will be asked to leave the room. This is normal procedure. The candidate is then invited back into the room afterwards and asked to give a 15 to 20 minute presentation on their research. It is permitted for the candidate to choose not to give this presentation, but candidates in the physics and astronomy department are encouraged to present.
Following the presentation, the committee will question the candidate. After this the candidate will be asked to leave the room once again while the committee determines the result of the exam. The results are then announced to the candidate, marking the conclusion of the examination.
The committee may pass the exam and thesis, with minor revisions to be dealt with by the supervisor and candidate, or they can require more major revisions that must be approved by the full committee. They can also fail the exam and/or the thesis, requiring a re-examination or re-submission within six months. In principle, an outright fail is also possible, but this is very rare.