Ph.D. students must plan their course of graduate study to develop special competence in a major field and substantial proficiency in several other fields of study. The major field corresponds to the general field in which the dissertation lies, and competence in the major field is tested by the Ph.D. Preliminary Examination (see below). The major field is defined in consultation between the candidate and the dissertation supervisor and with the approval of the Graduate Group.

Proficiency in other fields is demonstrated by coursework that fulfills the following distribution requirements:

1. Each student shall take courses with at least eight members of the
Graduate Group. Four of these courses shall be on the period before
1750, four on the period after.
2. Each student shall take two courses with at least three members of
the Graduate Group.

Students who transfer credits to the program from other institutions may petition to have these requirements relaxed. Students who transfer the maximum of eight credits must take courses with at least five members of the Graduate Group.