Preliminary Examination

Goals and Format (Students Matriculating after Fall 2022)

The Preliminary Examination (Prelim) assesses your competency in the broad field of statistical science, and preparedness for individual research in statistical science. The Prelim Exam will be primarily an oral exam on statistical theory, with some written components as described below. The exam will evaluate a student's technical competence relevant to statistics research in student elected areas of interest where the evaluators, also elected by the student, are potential research advisors in the chosen areas.  

In the Fall semester of the second year, each student in good standing (see below) will identify three primary faculty members in DSS as potential research advisors, who will be the Subject Matter Examiners on the Prelim committee.  To prepare for the Prelim, the student will enroll in a 1 credit STA 891 "Prelim Special Topics" course with each of the Subject Examiners during the semester in which the Prelim Exam will take place.

  • Exam Procedure:
    • The Prelim Exam will be administered by a committee of three DSS faculty members ("Subject Examiners") of the candidate's choice with approval from the DGS. The committee will have two additional members (Non-Subject Examiners) chosen by the department in consultation with the candidate (one from DSS who will be the chair of the committee and one member external to DSS). At least two of the three Subject Examiners must vote Pass for the candidate to pass the Prelim Exam. The role of the external member is to serve as an observer who submits a report to the DGS/department chair on how robustly and fairly the exam was administered.
    • The three subject examiners will each offer a 1 credit graded STA 891: Topics for Prelim independent study to ensure adequate progress of the student. Each of the three Subject Examiners will provide the candidate with a short written description of topics and relevant literature on which the exam will concentrate (see examples here). Each topic description will include a small set of questions that the candidate must attempt and submit in writing prior to the oral exam (for example, see the "Core topics" questions here). The written description of topics  from the subject matter examiner must be submitted by the student (or faculty member)  to the DGS/DGSA before permission numbers for the course will be provided to the student. This must happen by the second week of the semester in which the exam is taken (either Fall or Spring of Year 2) prior to Add/Drop
    • Once all three STA891s are created the prelim committee will be formally set with the Chair and External member specified by the Department.  
    •  After committee formation, the candidate will be given at least 2 months of preparation time before the main oral exam takes place. The oral exam will build upon the submitted answers and go farther and deeper in probing the candidate's understanding and mastery of core statistical theory relevant to statistics research on the topics of interest.
  • Outcome: 
    • Upon passing the exam, the candidate will be declared a doctoral candidate and will start dissertation research. The candidate is expected to choose one (or more) of the Subject Examiners as dissertation advisor(s); exceptions may be granted by the DGS upon a written petition by the candidate.
    • Upon failure, the candidate may choose to apply for a second examination with the consent of the exam committee (this requires unanimous consent of the examination committee and the DGS). The second exam must be held during 3 to 6 months of the first exam (this is in accordance to Graduate School policies for PhD preliminary exams). Successful completion of the second examination requires the affirmative vote of all original committee members. The default is that it will be administered by the same committee, as required by the Graduate School, but a petition to change a committee can be submitted to the DGS. The committee may decline a second examination and instead recommend that the candidate leave the program with an MS degree (subject to MS credit requirements; the preliminary exam will serve as the completion exercise for the MS). 


Satisfactory Progress.  The program shall be guided by the following additional formal requirements for 'satisfactory progress' (beyond the 3.0 GPA).


  • A GPA of 3.2 in the Core6+ graduate courses is required to take the exam.
  • Enrollment in 3 1 credit STA891 Topics for Prelim Independent Study and at least one other course worth 3 credits is required in each semester that the Prelim Exam is taken. 
  • An exam committee must be formed by the second week of the semester (end of Add/Drop) in which the exam is taken.
  • A student who does not take the exam in the Fall must enroll in a full course load (10 credits) in the Fall.  
  • Either pass the prelim exam or complete 36 credits before the end of Spring Year 2. 
  • Pass the prelim exam or leave program by end of Summer Year 2.
    • At the discretion of the prelim committee, a failed exam may be retaken within 3 months.  
    • A MSS degree (terminal or en route)  may be earned subject to 36 credit and completion exercise requirement. Taking the prelim exam counts as the MS completion exercise.

By the end of Year 2 a student will either pass the prelim exam or will have met the credit requirements for a terminal MS degree. 


Frequently Asked Questions


  1. When and how do I put together a committee? The goal in committee formation is to identify potential research advisors, who are expected to serve as the Subject Examiners in the Prelim Exam. We expect you to start discussing with potential research advisors sometime at the end of the first year and over the summer, during which time you will also narrow down potential topics and the Subject Examiners will provide you with the formal topic descriptions. The committee formation must be complete within the first two weeks of the Fall semester of year 2 for students who meet the aggregate GPA of 3.2. Students who do not meet the GPA are encouraged to identify Subject Examiners as early as possible, while taking additional courses to bring up their GPAs.
  2. If I came in knowing exactly who I wanted to work with, why and how should I choose the other Subject Examiners? Additional Subject Examiners play a key role to assess the breadth of your technical preparation and can also be vital in providing additional advising and perspectives in your future dissertation research. The DGS, your departmental advisor and your potential primary research advisor can help you identify these additional members.
  3. If I came in with little knowledge of statistics research, will one year be enough to identify research topics and potential advisors? What a student needs to identify at the time of the Prelim Exam are general areas of interest, not narrowly defined thesis topics. Developing ideas about research and finding faculty mentors will require a certain level of agency from the student. All first year students are required to take 701S (the PhD student seminar) which helps provide an overview of potential research areas and advisors. We also encourage first year students to interact broadly with senior students and faculty members to further develop ideas about research topics. The Summer Research Fellowship is designed to provide a window of time where more serious explorations can be done with active interactions with faculty members.
  4. What if I can't fully form the committee by the stipulated timeline (2nd week of Fall in year 2)? We encourage all students to check in with the DGS and Departmental Advisor during the summer if they are having difficulties identifying 3 Subject Examiners. A student can formally petition to delay the exam, but it is imperative that the DGS is aware of any such development as early as possible.
  5. What if I want to do an internship in my first summer? The prelim format does not preclude the possibility of an internship in the summer of year 1. However, a summer internship may slow down the process of identifying exam topics and examiners. An advanced student may still take the prelim exam in Fall. Others may need to defer the exam to spring, allowing themselves extra time to find topics and examiners. In case of a deferment, the student must enroll in a full course load in the Fall semester.
  6. How would the department evaluate competence in applied statistics? The Case Studies course (723) remains a program requirement and will serve as the formal assessment of applied statistics education. This course is counted as part of Core6 for which an aggregate 3.2+ GPA is needed.
  7. Are we expected/allowed to take courses in the Fall semester when the exam is scheduled? Students are allowed and encouraged to take courses, but may want to customize the load and the focus in discussion with their departmental advisors and Subject Examiners. At the minimum, 3 credit points will be awarded to a Prelim Exam candidate in the form of  independent studies  (with Subject Examiners as instructors). Additional credits may be earned as part of exam preparation if deemed appropriate by the committee and the DGS. Other regularly scheduled courses and mini courses may also be beneficial as part of exam and research preparedness.

Goals and Format (Students Matriculating in Fall 2021)

The Preliminary Examination (Prelim) assesses your competency in the broad field of statistical science, and preparedness for individual research in statistical science. With agreement of the advisor and Prelim Committee on topic(s), you will make a seminar-style presentation to the Committee, with questions from the Committee on the material presented, and associated material, as well as any other questions on statistics and related topics the Committee members choose.

The Prelim presentation material may comprise review and critique of published research (in one or two papers from the literature), or—more commonly—work you have developed in mentored independent study or as Research Assistant. It is common, but not required, that you present material you have been exploring that is already identified as a likely Ph.D. dissertation research topic.


  • Discuss potential Prelim Exam topics with advisor, and with other professors during your second year in the program.  Many students take STA 993 or STA 994 Independent Study in one or both semesters to develop expertise in an area in preparation for the Prelim.
  • Propose Prelim Committee, which must be approved by the Graduate School at least 30 days prior to the scheduled Prelim Exam (though can be changed arbitrarily, with approval, once established). You should aim to have the initial Committee and named chair/Prelim advisor, approved by the end of February, and schedule the exam in early May. The proposed Committee must follow these Graduate School and departmental regulations on Committee membership for what will become the Ph.D. Dissertation Committee following a successful Prelim.
  • Take Prelim Exam. Many students take the Prelim Exam in the summer session after the second year. In some cases the Prelim can be deferred until fall semester of the third year. The Prelim Exam must be passed by the end of the third year.