The initial stage includes a number of seminars, laboratory studies and classes in core subjects, which are essential for studies of this level. These are used to evaluate mastery of the field and critical, as well as independent thinking skills. Students must pass written examinations, called "writtens," "comprehensives" or just "comps." Success at this stage allow students to continue with their doctoral studies, a process formally called advancement to candidacy. In case of failure, students are withdrawn from the PhD program.
Students have to attend a number of advanced seminars and consortia, as they prepare for their thesis or dissertation. It is during this stage that candidates choose the topic of their dissertation, form a dissertation committee and start designing the steps towards completion of their research. The topic, as well as the research's design, must be approved by the committee and the individual's academic adviser before the candidate can start working on his dissertation.
The required research, as well as the comprehensive presentation of it on the candidate's dissertation, can take several years (usually between three and five years, according to the NORC). During this stage, students have to commit to their thesis, which is regularly inspected by their academic adviser. Since there are no deadlines imposed, dissertations are expected to be thorough, structured and understandable. When the academic adviser believes that the candidate's work meets at least the acceptable standards, it is scheduled for a dissertation defense and delivered to the members of the dissertation committee.
Candidates have to go through an oral examination by the dissertation committee, which consists of three to five senior professors in the particular research field, including the academic adviser. Candidates are expected to present their mastery of the subject, answering all the questions of the committee as well as justifying the findings of their research. If the candidates are successful in defending their work in front of the committee and invited guests, they will be awarded their PhD title.