For PhD students, the oral preliminary exam and the thesis defense presentation have two main purposes:

(i) To allow faculty to give useful feedback to the student on improvements, extensions, and future directions for research.

(ii) To verify that the student can give a clear, compelling, and eloquent 45-minute presentation on his or her research. Whether the student goes on to industry or academia, developing such a skill will be crucial not only in the interview process but also will be important for the student's future career success.

Note that "educating the faculty about the student's research" is not one of these two main purposes, and it is not essential nor even advisable that the student attempt to inform the faculty about all of his or her research findings.

Rather than lectures or exams, these events should really be thought of as opportunities for students to discuss their results with members of the UCLA faculty. The student's presentation is really only a small component; typically the most fruitful part of the process is the interaction and discussion between the faculty and the student.

To these ends, here is a timeline and advice for students preparing for these exams:

You will need to have 4 members on your committee: 3 should be from the Statistics department, and 1 must be from some outside department. Your primary thesis advisor counts as 1 of the 3 Statistics department faculty.

About 3 weeks before the exam, ask the faculty who you would like to serve on the committee if they are willing to participate, and arrange a date and time for the exam. This can simply be done by email. In your email, you should inform the faculty about the general subject of your research. Check with the department staff that the room is available at the time that you arrange.

Whether you are doing an oral preliminary exam or a thesis defense, you will need to prepare a written document. If you are advancing to candidacy and getting ready for your oral preliminary exam, you will need to submit a written prospectus of your oral exam to the committee. If you are finishing your PhD research and preparing for your thesis defense, then you should be finishing your dissertation. Either way, give a draft of your written document (either via email or an actual paper copy) to each of your committee members 1-2 weeks before the exam. To ensure that the file is not too big to transmit via email, one possibility is to place an electronic copy of the thesis on your website, and then send a link to the committee members in an email. The dissertation is usually a large document, and in our department these usually range from 70 to 130 pages. The written prospectus can be short. These should be a concise summary of your research plans, and while there are no page requirements, they are often roughly 20 pages in length. They can be organized like your talk, beginning with background information, showing your preliminary results, and outlining directions that your proposed research might go in.

1 week before the exam, meet with the student affairs officer to arrange that your files and paperwork are ready on the exam date. The student affairs office should arrange that a file consisting of paperwork documenting your progress as a student at UCLA be given directly to your advisor.

1 day before the exam, send the committee members an email reminding them of the exam's date, time, and location. Ask them to confirm receipt of your email.

1 hour before the exam, start to set up the projector, your laptop, etc. For your thesis defense, you should bring 2 or 3 copies of the signature page on the appropriate paper, for the committee to sign at the end. There is no need to bring food or drink for the committee members.

At the beginning of the exam, after greeting the committee members, you (the student) will be asked to leave the room briefly and close the door, in case any of the committee members have any questions or issues that they would prefer to discuss privately with your advisor. This usually only lasts for a minute or two. If it lasts longer, do not worry -- sometimes this is merely because the advisor is raving about how wonderful the student has been. Next, your advisor will open the door and let you back in, and you should begin your talk, which should last 45 minutes. During the talk there may be questions, and after your talk the committee members will also ask further questions and make comments and suggestions for about 5-10 minutes each. After this, you will be asked to leave the room again, so that the committee can privately discuss your case. This again typically takes just a couple minutes, after which time you can re-enter the room.

As indicated at the top of this page, the main purpose of these exams is for your committee members to provide feedback to you on your research. If you talk for longer than 45 minutes, there will be two main negative consequences: first, you will fail to verify that you are able to give a concise talk; second, your committee may not have ample time to engage in discussion and to provide you with useful suggestions which may help you in your future research. Thus, speaking for longer than 45 minutes detracts from both of the main purposes of the exam. In addition, it is also somewhat disrespectful to your exam committee.
At the beginning of your 45-minute presentation, address each of the following three questions for about 30 seconds each:
(a) Why is your research of interest to the statistics community?
(b) If your research involves an application, why would your results be important for any expert in that field of application?
(c) Why is your research important to all human beings?

For the oral preliminary exam, the primary focus should be on the research you plan to do, rather than on what you have already done so far. Spend about 25 minutes discussing background and your preliminary results, and then spend the remaining 20 minutes discussing your ideas for future research.

For the thesis defense, in order to ensure that your talk lasts 45 minutes without going overtime, one possibility is to discuss an overview of the main issues, ideas, and results at the beginning of your talk, and then fill in details as time permits, until 40 minutes has expired. Then spend the last 5 minutes concluding your talk, commenting on the significance of your main results and how they fit into the existing state of knowledge of the subject matter.

During your talk, it is important to face the committee as much as possible. However, it is not advisable to stare directly at any of your audience members in particular during the talk. Instead, speak to the room as a whole.
It is not necessary, during your 45-minute presentation, to present all of your results nor to present all of the details in your research. It is far more important that you provide a clear demonstration of the most important lines of your research. Think of your talk as giving the committee members the best possible overview of your research that will enable them to have constructive suggestions and future ideas for you.
Speak clearly, loudly, and confidently during your presentation and when answering questions afterwards. Remember that this really is not so much an exam as much as an opportunity for you to discuss your ideas with the faculty, so try to enjoy it and make the most of it.