Here is how a Ph.D. student's career goes.
In the first year, the student is expected to take courses and familiarize himself or herself with the activities of the various research groups in the Department. At the end of the year, four Comprehensive Examinations are administered. Each student is expected to pass at least two Comprehensive Exams in the first year and to have passed all four by the end of the second year.
After the first year, the student comes under the direction of a Supervisory Committee. Currently there are four principal Committees, in Artificial Intelligence, Programming Languages and Systems, Scientific Computing, and Theory of Computing, but additional Committees are formed ad hoc by the Faculty as the need arises. Each Committee is responsible for tracking a group of students and evaluating their progress. Once a student has selected a Supervisory Committee, any changes to the Committee require consultation among the Director of Graduate Studies, the old Committee, and the proposed new one.
In the second year, the student continues taking courses, completing a total of twelve courses by the end of the year. Two of these courses must be the CS 690 and CS 691 sequence, in which the student does a project under the direction of a faculty Advisor. The Advisor for the 690 Project should be chosen before the beginning of the second year.
In the fall term, the student gives the first local Official Graduate Student Talk (OGST) to his or her research group. Since research is just beginning, this talk can simply present a paper in the student's intended area of study. In the spring term, the student gives the first Departmental OGST. This will generally be a presentation of the work to date on the 690 Project and serves as a practice talk for the required 690 Project presentation. However, if the 690 Project is complete by the scheduled date of the OGST, the student's Committee may allow the OGST to be the 690 presentation as well.
The end of the second year is the culmination of two years of study and research. The student passes any remaining Comprehensive Exams not passed in the first year, passes an Area Exam demonstrating breadth of knowledge in the research area of the 690 Project, and finishes the 690 Project itself, presenting it to the Faculty in oral and written form.
By the start of the third year, the student chooses a Thesis Advisor and begins dissertation research. The Thesis Advisor is often the same as the 690 Advisor but doesn't have to be.
By the end of the third year, the student should have satisfied all pre-candidacy requirements, including writing a Thesis Prospectus that describes the general area and direction of the dissertation research. The student is then admitted to Candidacy by vote of the Faculty. The Graduate School will not allow a student to register for a fourth year of study until this step has been completed.
After admission to Candidacy, the student's position in the Department is secure, subject only to continued satisfactory progress toward completion of the Dissertation. When the Dissertation is complete, it is defended before the Faculty and approved by a Committee of Readers. The requirements for the Ph.D. have then been met and the degree is granted.