Generally, no more than two hours ought to be required. The chairman of the committee, who presides, is responsible for seeing that no examiner takes more than his or her allotted and appropriate share of the time available. 

Suggestions for the conduct of the examination:

1. A brief preliminary consultation is appropriate among the members of the committee on their reactions to the dissertation, as well as agreement on the general plan of the examination, the order in which questioners will be called upon, etc.
2. Then comes admission of the candidate to the examination room and introduction of the candidate and any faculty or others attending who do not know each other. Formal proceedings are opened by the chairman, who gives a brief resume of the candidate’s career to date.
3. At the conclusion of the examination, the candidate is asked to withdraw to a nearby area to await the committee’s decision. Under the presiding officer’s direction, the committee members discuss the candidate’s performance. When this discussion is concluded, the committee votes, and the votes are recorded on the “Report of Final Examination”. 
4. If the examination is satisfactory, the candidate is called back into the room to receive congratulations. If the examination is not satisfactory, the presiding officer should communicate that conclusion to the candidate privately. In case of serious disagreement among committee members, the question might be held in abeyance for a day or two to allow time for the reflection and further discussion, in which event the candidate should be informed that they will be notified shortly.
5. After the examination, the form that must be signed by the committee members are returned to the Graduate School.