Skip to main content
Department of Statistics

Ph.D. Examinations

Ph.D. Qualifying Exam

Besides taking required course work, Ph.D. students must pass the qualifying exam, written and oral preliminary exams, write a dissertation and pass a final oral exam. For students entering with a previous Master’s degree in Statistics, the qualifying exam should be taken within one year of entering the program.

Ph.D. Preliminary Exams

Deadline: Each PhD student is required to:

  1. Successfully pass the PhD Written Prelim Exam within 18 months from the date of successfully passing the PhD Qualifying Exam.
  2. Achieve at least a conditional pass on the PhD Oral Prelim Exam after passing the Written Prelim. This must be no more than 26 months from the date of successfully passing the PhD Qualifying Exam. If the student receives a conditional pass, then the committee will abide by the graduate school policies on conditional passes and reexaminations given by https://grad.ncsu.edu/students/rules-and-regulations/handbook/3-5-comprehensive-examinations/

Procedure: Once a student has formed an advisory committee and the committee has approved the PhD Plan of Work, the student can work with the committee to arrange the schedule for the PhD Written Prelim Exam. The committee should inform the Graduate Secretary of the starting date for the exam. Upon successful completion of the Written Prelim Exam, the Oral Prelim Exam can be scheduled with a minimum of 14 business day notice to the Graduate Secretary.

Any potential deviations from the above timeframe should be discussed with the committee and the Director of Graduate Programs.

Format for Written Prelim: The written prelim document will consist of an extended review paper on a topic that is proposed by the student’s committee. At an agreed upon time between the student and their committee, the student will meet with the committee to discuss the topic and set up guidelines and expectations in order to give the student a start on the document. The student will then have 30 days to complete the written document.

The exam is to be completed by the student with no external assistance. Students may not discuss their exam with faculty, other students, or any other person not approved by the committee. Any clarifications or questions should be addressed to the committee. Cheating of any type (e.g., plagiarism, soliciting help from others) will result in a failing grade. Failure of this exam is grounds for dismissal from the graduate program. Students are advised to familiarize themselves with the many guises of plagiarism. It is your responsibility to know what constitutes plagiarism, and to ensure against it.

The committee will decide on the problem formulation, which may be based on the student’s current work, or other potential areas for investigation. The document should introduce the topic area at a level that would be understandable by anyone with a PhD in statistics but not necessarily familiar with the topic area. Thus the student will need to identify, obtain, read, and assimilate the main developments in the area both from the existing literature, and from the student’s own work. The student should define terms that are not generally known by people outside the topic area. Key statistical issues and problems should be described. Discussion of main existing results and their evolution should be presented. Open questions for future research should be identified. There should be some technical details and displayed equations in the paper. One should strike a balance between the extremes of no equations (very nontechnical) and too many equations. The written prelim exam should also include a small simulation study to compare some of the methods that have been reviewed. Please refer to the guidelines for Monte Carlo studies given in the Statistics Graduate Program Handbook to conduct and report simulations. 

The report should be typewritten and contain no spelling errors. A consistent style and notation should be used throughout. Choice of a common notation should be made by the student. It might be helpful to consult the style guidelines on the web for a journal such as Biometrics, JASA, or Genetics for suggestions on format of text, tables, and figures, conventions for references and citations, and general style of presentation. There is no specific page-length requirement; it is up to the committee members to judge the completeness of the paper, but a suggested length is that the main paper should not exceed 20 pages and with simulations the total length should not exceed 25 pages.

The committee will review the paper, and decide whether or not it is satisfactory to continue in the program. In most cases, comments will be given by the committee and the student will have 30 days to revise the paper addressing the specific comments. The final decision would then be made after reviewing the revised paper. This may differ from one committee to the next.

Format for Oral Prelim: he preliminary oral examination may be scheduled only after the student has passed the Preliminary Written Exam and has the advisory committee and POW approved by the Graduate School. Though the format of the oral preliminary examination may vary according to the committee, as a general guideline it will include three elements.

      1. Presentation by the candidate. The candidate makes a presentation of the current state of the research, including a proposal for the future research work to be conducted. This presentation is open only to the committee and any other NCSU graduate faculty member that wishes to attend. It is not open to other students, friends, or family members.
      2. Questioning of the candidate. Anyone attending the presentation will be allowed to ask questions of the candidate during, and at the conclusion of the presentation. Once the general questioning is completed, the committee chair will reconvene the questioning phase in closed session in which only the advisory committee questions the candidate.
      3. Deliberation and decision. Only the advisory committee and the Graduate School representative, if one has been appointed, will be allowed to participate in the deliberation and decision.

Throughout the process, the chair of the candidate’s advisory committee has the obligation to maintain a scholarly atmosphere and to keep academic integrity and the student’s best interest foremost.

The Exam result will be either (1) an unconditional pass, (2) a conditional pass (with explicitly stated conditions for the student to address), or (3) a failure. In case (2) or (3), the committee will abide by the graduate school policies on conditional passes and reexaminations given by https://grad.ncsu.edu/students/rules-and-regulations/handbook/3-5-comprehensive-examinations/

Ph.D. Final Oral Examination

The Ph.D. final oral examination consists of a defense by the candidate of the methodology used and conclusions reached in the dissertation. The dissertation must embody results of original research of a standard that would warrant publication in a statistics research journal. Publication of research in established journals is highly encouraged, regardless of whether you plan to work at a university or at a company. At least FOUR months are required to elapse between the date of an unconditional pass on the preliminary oral exam and the scheduling of the final oral exam. The four-month interval begins with the date when ALL conditions are satisfied and this date may not necessarily be the original date of the preliminary oral exam. As with the preliminary oral exam, it is the student’s responsibility to find a date and time that is acceptable to all members of his/her advisory committee (including the Graduate School Representative) and to notify the graduate secretary at least 15 working days prior to the proposed exam date. The graduate secretary will then reserve a room and make the necessary arrangements with the Graduate School. Unless carefully planned in advance, summer oral exams are difficult to schedule and committee substitutions cannot be guaranteed, especially since a dissertation is involved. It is also the responsibility of the student to provide a typed copy of the dissertation to each committee member at least two weeks prior to the exam. As a courtesy, the student should also offer to provide the Graduate School Representative with a copy. Final oral exams open to university community. Ph.D. Final Oral exams consist of an open seminar followed by questions from the committee in a closed session.