The Graduate School of Arts and Sciences requires that all doctoral dissertations undergo a formal examination in which the student has the opportunity to discuss and defend the dissertation with respect to its sources, findings, interpretations, and conclusions before a committee of faculty knowledgeable in the student's field of research. All faculty members of the defense committee are expected to be present at the defense.
Only the candidate and the approved members of the dissertation defense committee may be present during the defense. Columbia University policy never allows spectators or other individuals to attend a defense. There are no exceptions to this rule.
The defense must be conducted in English.
Participation in Doctoral Dissertation Defenses
The dissertation defense is a milestone ideally reached with all five members of a student’s dissertation committee present. When a committee member can only participate from afar, an accommodation may be made by employing audio or video conferencing during the defense. A maximum of two members of the dissertation defense committee may participate remotely, but the committee chair and the sponsor must be present at the defense.
The committee chair will register the need for remote participation on the GSAS Application for the Dissertation Defense (.pdf), and will sign the voting sheet on the absent member’s behalf after the defense. Committee members who must participate remotely are requested to submit comments, questions, and a provisional vote in advance so that the defense exercise may proceed in the event technical difficulties are encountered during the proceedings.
Committee Member Absence in Exceptional Circumstances
The dissertation defense committee may convene when one member is prevented from participating by extreme circumstances at the time of the defense. Such a last-minute absence will count toward the total of two members allowed to participate remotely. If possible, the absent member should submit before the defense a report containing comments, questions, and a provisional vote on the dissertation's approval. The committee chair will convey these questions to the candidate at the defense and rule on the quality the responses made. If circumstances prevent the submission of a report before the defense, the absent member’s report should be sent as soon as possible after the defense to the dissertation defense committee chair and to the Dean of the Graduate School. The committee vote will not be considered final until the report is reviewed and the defense committee chair determines whether any further action is warranted.
The examination normally lasts two hours. The candidate is generally asked to begin by summarizing the pertinent background and findings. Such summaries should be limited to five minutes. The Chair of the Committee is responsible for allotting time, normally allowing each faculty member 20 minutes in which to examine the candidate.
Typically examiners provide lists of points they wish to discuss. These points are either substantial or editorial. Unless it is necessary to show that a very poorly written dissertation must be entirely rewritten, examiners should not take up these editorial comments one by one. Examiners should give their sheets of notes on these matters to the candidate, leaving time to examine matters of substance.
When all examiners have finished their questioning, the Chair asks the candidate to step outside and wait for a signal to return. The committee rises on the candidate's leaving and entering.
During the discussion period, the Committee makes its decision on the defense. The three possible decisions are Pass, Incomplete or Fail.
The Vote: Pass, Incomplete or Fail
The dissertation is deemed acceptable subject to minor revisions.
The dissertation is revised by the candidate in light of the comments made by the committee, and the revisions are supervised by the student's sponsor. Usually it is not necessary to seek approval from the defense committee for minor revisions, provided the approval card is signed by the sponsor and department/program chair. The defense committee, however, reserves the right to review those revisions. Upon completion of the required revisions, the candidate is recommended for the degree.
The candidate must complete all revisions and deposit the dissertation no later than six months from the date of the dissertation defense. A unanimous vote or a vote with only one dissent in a lower column constitutes a pass. In the case of three votes for pass and two for incomplete or fail, the voting sheet and dissertation must be submitted to the Dean for review and the candidate should be informed that the committee's vote was not conclusive and he/she should await further communication from the Dean.
The dissertation is deemed acceptable subject to major revisions. Upon completion and acceptance of the required revisions, the defense is considered to be successful and the vote is changed to Pass.
Where a dissertation is considered incomplete (i.e. acceptable subject to major revisions,) the Chair of the Defense Committee is required to form a revisions subcommittee made up of one to three members of the original committee, whose names must be entered as such on the Voting Sheet. Usually the sponsor of the dissertation is chair of the subcommittee; the other members should be those committee members who have made the most extensive objections to the text as it stands. When the student has finished the major revisions, he or she must submit the revised dissertation to each of the members of the revisions subcommittee. Specified revisions must be made and the approved copies submitted to the revisions subcommittee no earlier than three months and no later than one year after the defense unless otherwise directed by the committee. If the revised dissertation is accepted by the subcommittee, each member of the revisions subcommittee must confirm acceptance in writing to the Dissertation Office. Once all these letters arrive, the Dissertation Office changes the vote from “Incomplete” to “Pass,” and the candidate may deposit the dissertation.
If the candidate fails to submit a revised dissertation to the revisions subcommittee by the deadline, the vote will be changed from "Incomplete" to "Fail." A second defense is not permitted.
The dissertation is deemed unacceptable and the candidate is not recommended for the degree. No candidate may have a second defense unless the Dean considers, upon the evidence provided, that the first one involved procedural irregularities.